Comment 60 for bug 1872118

Just tried this
apt-get -y remove isc-dhcp-server
apt-get -y remove libdns-export1109/focal-proposed
apt-get -y remove libirs-export161/focal-proposed
apt-get -y remove libisc-export1105/focal-proposed
apt-get -y install isc-dhcp-server
apt-get -y install libdns1109/focal-proposed
apt-get -y install libirs161/focal-proposed
apt-get -y install libisc1105/focal-proposed

GW1
# dpkg -l | grep isc-dhcp-server
ii isc-dhcp-server 4.4.1-2.1ubuntu5 amd64 ISC DHCP server for automatic IP address assignment
# dpkg -l | grep libdns
ii libdns-export1100 1:9.11.3+dfsg-1ubuntu1.12 amd64 Exported DNS Shared Library
ii libdns-export1109 1:9.11.16+dfsg-3~build1 amd64 Exported DNS Shared Library
ii libdns1109:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 DNS Shared Library used by BIND
# dpkg -l | grep libirs
ii libirs-export160 1:9.11.3+dfsg-1ubuntu1.12 amd64 Exported IRS Shared Library
ii libirs-export161 1:9.11.16+dfsg-3~build1 amd64 Exported IRS Shared Library
ii libirs161:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 DNS Shared Library used by BIND
# dpkg -l | grep libisc
ii libisc-export1105:amd64 1:9.11.16+dfsg-3~build1 amd64 Exported ISC Shared Library
ii libisc-export169:amd64 1:9.11.3+dfsg-1ubuntu1.12 amd64 Exported ISC Shared Library
ii libisc1105:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 ISC Shared Library used by BIND
ii libisccc161:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 Command Channel Library used by BIND
ii libisccfg-export160 1:9.11.3+dfsg-1ubuntu1.12 amd64 Exported ISC CFG Shared Library
ii libisccfg-export163 1:9.11.16+dfsg-3~build1 amd64 Exported ISC CFG Shared Library
ii libisccfg163:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 Config File Handling Library used by BIND

GW2
# dpkg -l | grep isc-dhcp-server
ii isc-dhcp-server 4.4.1-2.1ubuntu5 amd64 ISC DHCP server for automatic IP address assignment
# dpkg -l | grep libdns
ii libdns-export1100 1:9.11.3+dfsg-1ubuntu1.12 amd64 Exported DNS Shared Library
ii libdns-export1109 1:9.11.16+dfsg-3~build1 amd64 Exported DNS Shared Library
ii libdns1109:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 DNS Shared Library used by BIND
# dpkg -l | grep libirs
ii libirs-export160 1:9.11.3+dfsg-1ubuntu1.12 amd64 Exported IRS Shared Library
ii libirs-export161 1:9.11.16+dfsg-3~build1 amd64 Exported IRS Shared Library
ii libirs161:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 DNS Shared Library used by BIND
# dpkg -l | grep libisc
ii libisc-export1105:amd64 1:9.11.16+dfsg-3~build1 amd64 Exported ISC Shared Library
ii libisc-export169:amd64 1:9.11.3+dfsg-1ubuntu1.12 amd64 Exported ISC Shared Library
ii libisc1105:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 ISC Shared Library used by BIND
ii libisccc161:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 Command Channel Library used by BIND
ii libisccfg-export160 1:9.11.3+dfsg-1ubuntu1.12 amd64 Exported ISC CFG Shared Library
ii libisccfg-export163 1:9.11.16+dfsg-3~build1 amd64 Exported ISC CFG Shared Library
ii libisccfg163:amd64 1:9.11.16+dfsg-3~ubuntu1 amd64 Config File Handling Library used by BIND

still not good