(Relatively) simple fix:
systemctl stop systemd-resolvd
systemctl disable systemd-resolvd
Edit /etc/NetworkManager/NetworkManager.conf And in the [main]
section stick this:
[main]
dns=none
Now rm -f /etc/resolv.conf
Now create your own /etc/resolv.conf file from scratch with
the nameserver and search directives you actually want.
Systemd won't stick its nose in, NetworkManager won't clobber
your resolve.conf file, your network will actually function :-).