Comment 16 for bug 1755383

nmbd (the netbios name resolution daemon) will not work on a ppp0 link, because it doesn't have a broadcast address.

I suggest you disable the samba services if you are not going to use them very often, or at least disable the nmbd one. And only bring them up when you actually want to share something on your local network and have eth0 up and connected.

To disable nmbd:

sudo systemctl stop nmbd.service # might fail because it's not running, that's ok
sudo systemctl disable nmbd.service

To disable smbd, it's similar:
sudo systemctl stop smbd.service
sudo systemctl disable smbd.service

Then tell apt to try to fix the remaining installation issues:
sudo apt update
sudo apt -f install

The message below which you might still see is harmless:
/usr/bin/deb-systemd-helper: error: systemctl preset failed on samba-ad-dc.service: No such file or directory

Whenever you want to use samba again, run the systemctl commands again with "start" instead of "stop". Or remove the samba-common packages altogether.