Sure. I sought out the logs i thought most pertaining to the issue:

################

Preliminary information:

At 9:29:35 the rackD reports not being able to report test results. This corresponds with the following entry in kern.log:

Jun  8 09:29:35 maas-rackd001 kernel: [749024.447228] audit: type=1400 audit(1686216575.729:26065): apparmor="DENIED" operation="open" profile="snap.maas.supervisor" name="/etc/wgetrc" pid=3025042 comm="wget" requested_mask="r" denied_mask="r" fsuid=0 ouid=0

ens18 is the interface to which RACKD001_ADDRESS is bound.

################


MAAS RackD logs:

2023-06-08 09:28:29 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha003:pid=2832963) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:28:29 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha003:pid=2832963) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:28:29 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha003:pid=2832963) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:28:36 provisioningserver.utils.services: [warn] Couldn't report test results: HTTP error [500]
2023-06-08 09:28:39 ClusterClient,client: [info] ClusterClient connection lost (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=36090, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND002_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:28:39 ClusterClient,client: [info] ClusterClient connection lost (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=36100, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND002_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:28:39 ClusterClient,client: [info] ClusterClient connection lost (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=36112, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND002_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:28:59 Uninitialized: [info] ClusterClient connection established (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=57688, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND002_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:28:59 Uninitialized: [info] ClusterClient connection established (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=57702, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND002_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:28:59 Uninitialized: [info] ClusterClient connection established (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=57708, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND002_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:28:59 provisioningserver.rpc.clusterservice: [info] Event-loop 'maas-regiond-ha002:pid=2854011' authenticated.
2023-06-08 09:28:59 provisioningserver.rpc.clusterservice: [info] Event-loop 'maas-regiond-ha002:pid=2854011' authenticated.
2023-06-08 09:28:59 provisioningserver.rpc.clusterservice: [info] Event-loop 'maas-regiond-ha002:pid=2854011' authenticated.
2023-06-08 09:28:59 twisted.internet.defer: [critical] Unhandled error in Deferred:
2023-06-08 09:28:59 twisted.internet.defer: [critical]
	Traceback (most recent call last):
	Failure: twisted.internet.error.MulticastJoinError: (b'\xe0\x00\x00v', b'\n\x04\x00\x0c', 98, 'Address already in use')

2023-06-08 09:28:59 twisted.internet.defer: [critical] Unhandled error in Deferred:
2023-06-08 09:28:59 twisted.internet.defer: [critical]
	Traceback (most recent call last):
	Failure: twisted.internet.error.MulticastJoinError: (b'\xe0\x00\x00v', b'\n\x1e\x00\x0c', 98, 'Address already in use')

2023-06-08 09:28:59 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha002:pid=2854011) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:28:59 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha002:pid=2854011) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:28:59 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha002:pid=2854011) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:29:05 provisioningserver.utils.services: [warn] Couldn't report test results: HTTP error [500]
2023-06-08 09:29:09 ClusterClient,client: [info] ClusterClient connection lost (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=52690, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND003_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:29:09 ClusterClient,client: [info] ClusterClient connection lost (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=52698, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND003_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:29:09 ClusterClient,client: [info] ClusterClient connection lost (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=52706, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND003_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:29:29 Uninitialized: [info] ClusterClient connection established (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=36110, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND003_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:29:29 Uninitialized: [info] ClusterClient connection established (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=36126, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND003_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:29:29 Uninitialized: [info] ClusterClient connection established (HOST:IPv6Address(type='TCP', host='::ffff:RACKD001_ADDRESS', port=36136, flowInfo=0, scopeID=0) PEER:IPv6Address(type='TCP', host='::ffff:REGIOND003_ADDRESS', port=5252, flowInfo=0, scopeID=0))
2023-06-08 09:29:29 provisioningserver.rpc.clusterservice: [info] Event-loop 'maas-regiond-ha003:pid=2832965' authenticated.
2023-06-08 09:29:29 provisioningserver.rpc.clusterservice: [info] Event-loop 'maas-regiond-ha003:pid=2832965' authenticated.
2023-06-08 09:29:29 provisioningserver.rpc.clusterservice: [info] Event-loop 'maas-regiond-ha003:pid=2832965' authenticated.
2023-06-08 09:29:29 twisted.internet.defer: [critical] Unhandled error in Deferred:
2023-06-08 09:29:29 twisted.internet.defer: [critical]
	Traceback (most recent call last):
	Failure: twisted.internet.error.MulticastJoinError: (b'\xe0\x00\x00v', b'\n\x04\x00\x0c', 98, 'Address already in use')

2023-06-08 09:29:29 twisted.internet.defer: [critical] Unhandled error in Deferred:
2023-06-08 09:29:29 twisted.internet.defer: [critical]
	Traceback (most recent call last):
	Failure: twisted.internet.error.MulticastJoinError: (b'\xe0\x00\x00v', b'\n\x1e\x00\x0c', 98, 'Address already in use')

2023-06-08 09:29:29 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha003:pid=2832965) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:29:29 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha003:pid=2832965) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:29:29 provisioningserver.rpc.clusterservice: [info] Rack controller 'gqhhy7' registered (via maas-regiond-ha003:pid=2832965) with MAAS version 3.3.3-13184-g.3e9972c19.
2023-06-08 09:29:35 provisioningserver.utils.services: [warn] Couldn't report test results: HTTP error [500]


################


This is the syslog:

Jun  8 09:28:06 maas-rackd001 systemd[1]: Started snap.maas.maas.e5c47c61-ba31-42cb-af8e-95245d6acccb.scope.
Jun  8 09:28:08 maas-rackd001 systemd[1]: snap.maas.maas.e5c47c61-ba31-42cb-af8e-95245d6acccb.scope: Deactivated successfully.
Jun  8 09:28:08 maas-rackd001 systemd[1]: snap.maas.maas.e5c47c61-ba31-42cb-af8e-95245d6acccb.scope: Consumed 2.789s CPU time.
Jun  8 09:28:12 maas-rackd001 dhcpd[3023368]: peer failover-vlan-5001: disconnected
Jun  8 09:28:12 maas-rackd001 dhcpd[3023368]: failover peer failover-vlan-5001: I move from normal to communications-interrupted
Jun  8 09:28:13 maas-rackd001 dhcpd[3023368]: failover peer failover-vlan-5001: peer moves from normal to normal
Jun  8 09:28:13 maas-rackd001 dhcpd[3023368]: failover peer failover-vlan-5001: I move from communications-interrupted to normal
Jun  8 09:28:13 maas-rackd001 dhcpd[3023368]: failover peer failover-vlan-5001: Both servers normal
Jun  8 09:28:13 maas-rackd001 dhcpd[3023368]: balancing pool 55ba17a3a0f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-own (+/-)13
Jun  8 09:28:13 maas-rackd001 dhcpd[3023368]: balanced pool 55ba17a3a0f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-misbal 19
Jun  8 09:28:35 maas-rackd001 kernel: [748964.643610] audit: type=1400 audit(1686216515.823:26063): apparmor="DENIED" operation="open" profile="snap.maas.supervisor" name="/etc/wgetrc" pid=3024900 comm="wget" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Internet Systems Consortium DHCP Server 4.4.1
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Copyright 2004-2018 Internet Systems Consortium.
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: All rights reserved.
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: For info, please visit https://www.isc.org/software/dhcp/
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Config file: /var/snap/maas/common/maas/dhcpd.conf
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Database file: /var/snap/maas/common/maas/dhcp/dhcpd.leases
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: PID file: /var/snap/maas/common/maas/dhcp/dhcpd.pid
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Wrote 0 class decls to leases file.
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Wrote 0 deleted host decls to leases file.
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Wrote 0 new dynamic host decls to leases file.
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Wrote 83 leases to leases file.
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Listening on LPF/ens18/MA:CA:DR:ES:S1/vlan-5001
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Sending on   LPF/ens18/MA:CA:DR:ES:S1/vlan-5001
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Sending on   Socket/fallback/fallback-net
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: failover peer failover-vlan-5001: I move from normal to startup
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: Server starting service.
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: failover peer failover-vlan-5001: peer moves from normal to communications-interrupted
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: failover peer failover-vlan-5001: I move from startup to normal
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: balancing pool 55c90564d0f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-own (+/-)13
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: balanced pool 55c90564d0f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-misbal 19
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: failover peer failover-vlan-5001: peer moves from communications-interrupted to normal
Jun  8 09:28:57 maas-rackd001 dhcpd[3024913]: failover peer failover-vlan-5001: Both servers normal
Jun  8 09:29:05 maas-rackd001 kernel: [748994.448792] audit: type=1400 audit(1686216545.700:26064): apparmor="DENIED" operation="open" profile="snap.maas.supervisor" name="/etc/wgetrc" pid=3024961 comm="wget" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Internet Systems Consortium DHCP Server 4.4.1
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Copyright 2004-2018 Internet Systems Consortium.
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: All rights reserved.
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: For info, please visit https://www.isc.org/software/dhcp/
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Config file: /var/snap/maas/common/maas/dhcpd.conf
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Database file: /var/snap/maas/common/maas/dhcp/dhcpd.leases
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: PID file: /var/snap/maas/common/maas/dhcp/dhcpd.pid
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Wrote 0 class decls to leases file.
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Wrote 0 deleted host decls to leases file.
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Wrote 0 new dynamic host decls to leases file.
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Wrote 83 leases to leases file.
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Listening on LPF/ens18/MA:CA:DR:ES:S1/vlan-5001
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Sending on   LPF/ens18/MA:CA:DR:ES:S1/vlan-5001
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Sending on   Socket/fallback/fallback-net
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: I move from normal to startup
Jun  8 09:29:12 maas-rackd001 dhcpd[3024983]: Server starting service.
Jun  8 09:29:17 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: peer moves from normal to communications-interrupted
Jun  8 09:29:17 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: I move from startup to normal
Jun  8 09:29:17 maas-rackd001 dhcpd[3024983]: balancing pool 55d3f4e390f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-own (+/-)13
Jun  8 09:29:17 maas-rackd001 dhcpd[3024983]: balanced pool 55d3f4e390f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-misbal 19
Jun  8 09:29:17 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: peer moves from communications-interrupted to normal
Jun  8 09:29:17 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: Both servers normal
Jun  8 09:29:35 maas-rackd001 kernel: [749024.447228] audit: type=1400 audit(1686216575.729:26065): apparmor="DENIED" operation="open" profile="snap.maas.supervisor" name="/etc/wgetrc" pid=3025042 comm="wget" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
Jun  8 09:29:42 maas-rackd001 chronyd[822]: Selected source NTPSERVER_IPADDRESS (ntp.foo.net)Jun  8 09:29:59 maas-rackd001 dhcpd[3024983]: peer failover-vlan-5001: disconnected
Jun  8 09:29:59 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: I move from normal to communications-interrupted
Jun  8 09:29:59 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: peer moves from normal to normal
Jun  8 09:29:59 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: I move from communications-interrupted to normal
Jun  8 09:29:59 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: Both servers normal
Jun  8 09:29:59 maas-rackd001 dhcpd[3024983]: balancing pool 55d3f4e390f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-own (+/-)13
Jun  8 09:29:59 maas-rackd001 dhcpd[3024983]: balanced pool 55d3f4e390f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-misbal 19
Jun  8 09:30:05 maas-rackd001 kernel: [749054.381614] audit: type=1400 audit(1686216605.571:26066): apparmor="DENIED" operation="open" profile="snap.maas.supervisor" name="/etc/wgetrc" pid=3025099 comm="wget" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
Jun  8 09:30:13 maas-rackd001 dhcpd[3024983]: peer failover-vlan-5001: disconnected
Jun  8 09:30:13 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: I move from normal to communications-interrupted
Jun  8 09:30:13 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: peer moves from normal to normal
Jun  8 09:30:13 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: I move from communications-interrupted to normal
Jun  8 09:30:13 maas-rackd001 dhcpd[3024983]: failover peer failover-vlan-5001: Both servers normal
Jun  8 09:30:13 maas-rackd001 dhcpd[3024983]: balancing pool 55d3f4e390f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-own (+/-)13
Jun  8 09:30:13 maas-rackd001 dhcpd[3024983]: balanced pool 55d3f4e390f0 vlan-5001  total 127  free 64  backup 63  lts 0  max-misbal 19
Jun  8 09:30:35 maas-rackd001 kernel: [749084.630043] audit: type=1400 audit(1686216635.710:26067): apparmor="DENIED" operation="open" profile="snap.maas.supervisor" name="/etc/wgetrc" pid=3025182 comm="wget" requested_mask="r" denied_mask="r" fsuid=0 ouid=0
Jun  8 09:31:05 maas-rackd001 kernel: [749114.322276] audit: type=1400 audit(1686216665.324:26068): apparmor="DENIED" operation="open" profile="snap.maas.supervisor" name="/etc/wgetrc" pid=3025270 comm="wget" requested_mask="r" denied_mask="r" fsuid=0 ouid=0