network broken after March 4 updates

I have two Kubuntu machines based on Ubuntu 20.04, x86_64. The machines use a script to auto-update each night. The script performs an 'apt-get update && apt-get upgrade' each night around 4:00 AM as a systemd service.

When I woke this morning I could not connect to either machine. The wired network connection cycles from dectivated->activated->deactivated. It is just bouncing. I enabled wifi and tried to bring up the network but I had other problems. I seem to be getting a 10.0.0.xxx address so the network is also down.

Dmesg does not show errors related to networking.

Machine 1:

# dmesg | grep -i -E 'eth|enp|error|warn'
[ 0.729439] RAS: Correctable Errors collector initialized.
[ 1.013015] wmi_bus wmi_bus-PNP0C14:02: WQBC data block query control method not found
[ 1.020067] alx 0000:04:00.0 eth0: Qualcomm Atheros AR816x/AR817x Ethernet [d8:9e:f3:92:24:60]
[ 1.035103] alx 0000:04:00.0 enp4s0: renamed from eth0
[ 4.290092] EXT4-fs (nvme0n1p2): re-mounted. Opts: errors=remount-ro. Quota mode: none.
[ 5.017326] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 5.113378] alx 0000:04:00.0 enp4s0: NIC Up: 1 Gbps Full
[ 5.113647] IPv6: ADDRCONF(NETDEV_CHANGE): enp4s0: link becomes ready

Machine 2:

 dmesg | grep -i -E 'eth|enp|error|warn'
[ 4.886623] ACPI BIOS Error (bug): AE_AML_PACKAGE_LIMIT, Index (0x000000005) is beyond end of object (length 0x5) (20210331/exoparg2-393)
               Initialized Local Variables for Method [GETP]:
[ 4.886652] Initialized Arguments for Method [GETP]: (2 arguments defined for method invocation)
[ 4.886667] ACPI Error: Aborting method \_TZ.GETP due to previous error (AE_AML_PACKAGE_LIMIT) (20210331/psparse-529)
[ 4.886677] ACPI Error: Aborting method \_TZ.CHGZ._CRT due to previous error (AE_AML_PACKAGE_LIMIT) (20210331/psparse-529)
[ 4.887690] ACPI BIOS Error (bug): AE_AML_PACKAGE_LIMIT, Index (0x000000005) is beyond end of object (length 0x5) (20210331/exoparg2-393)
               Initialized Local Variables for Method [GETP]:
[ 4.887713] Initialized Arguments for Method [GETP]: (2 arguments defined for method invocation)
[ 4.887727] ACPI Error: Aborting method \_TZ.GETP due to previous error (AE_AML_PACKAGE_LIMIT) (20210331/psparse-529)
[ 4.887736] ACPI Error: Aborting method \_TZ.CHGZ._CRT due to previous error (AE_AML_PACKAGE_LIMIT) (20210331/psparse-529)
[ 5.463994] RAS: Correctable Errors collector initialized.
[ 5.856324] e1000e 0000:00:1f.6 eth0: (PCI Express:2.5GT/s:Width x1) 80:e8:2c:4c:27:27
[ 5.856327] e1000e 0000:00:1f.6 eth0: Intel(R) PRO/1000 Network Connection
[ 5.856405] e1000e 0000:00:1f.6 eth0: MAC: 12, PHY: 12, PBA No: FFFFFF-0FF
[ 5.857243] e1000e 0000:00:1f.6 enp0s31f6: renamed from eth0
[ 7.896863] EXT4-fs (nvme0n1p2): re-mounted. Opts: errors=remount-ro. Quota mode: none.
[ 8.223779] hp_wmi: query 0x4 returned error 0x5
[ 8.234838] hp_wmi: query 0xd returned error 0x5
[ 8.285693] hp_wmi: query 0x1b returned error 0x5
[ 8.633150] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[ 11.858857] e1000e 0000:00:1f.6 enp0s31f6: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: Rx/Tx
[ 11.858982] IPv6: ADDRCONF(NETDEV_CHANGE): enp0s31f6: link becomes ready

The one hint I have is, /var/log/apt/history.log shows a new linux-firmware was installed on both machines. This appears to be the only change on the day before trouble started:

Start-Date: 2022-03-04 04:19:40
Commandline: apt-get upgrade -y
Upgrade: linux-firmware:amd64 (1.187.26, 1.187.27)
End-Date: 2022-03-04 04:20:24

I've tried reinstalling network-manager with no joy.

Any help is appreciated.