I think this issue https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/486 might provide a fix. See also https://bugzilla.redhat.com/show_bug.cgi?id=1829178 where they mention the fix has been backported to 1.22.12. Any chance the Focal package could be upgraded to include that patch level? FWIW we've had the same issue as described on several machines (same network) when upgrading to Focal; installing the Groovy NM package (1.26.2) rebuilt from source for Focal seems to have fixed it.
** Bug watch added: Red Hat Bugzilla #1829178 https://bugzilla.redhat.com/show_bug.cgi?id=1829178 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1906120 Title: NetworkManager: error -111 disaptching events on DHCPv4 lease renewal To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1906120/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs