Comment 2 for bug 2055012

My case was exactly the same. And I also did the same as you at first (fixing /etc/resolv.conf by hand). After that I've realized that doing `sudo apt install systemd-resolved` seems to fix the situation better (/etc/resolv.conf is a link again, but now it's not broken). Also, `netplan status` reported to be offline before and says it's online now. `resolvectl status` lets you see your dhcp configured dns servers.

So, maybe failure in migrating network configurations prevented systemd-resolved to be installed, for some reason. BTW, in my case, the network I am currently connected to was migrated ok (I had a netplan file for it in /etc/netplan). The ones giving problems were other ones referring to other locations (my parents' home and such) that were not reachable at the moment of doing the migration.