Comment 1 for bug 1837795

Could you uninstall openvpn-systemd-resolved with

sudo apt purge openvpn-systemd-resolved

and then reboot?

The openvpn-systemd-resolved is actually not needed for network-manager with systemd-resolved in Ubuntu.

Does this solve your problem?

If not, please run the command

systemd-resolve --status

for both cases and post the full output here.

Also provide a debug log of Network Manager for both cases following the instructions on

https://wiki.ubuntu.com/DebuggingNetworkManager

and attach the resulting files here. Please do not compress the files and do not package them together.