I believe you could let #NetworkManager set /etc/resolv.conf with data it receives from DHCP for each connection. Removing the symlink, or pointing it to /run/NetworkManager/no-stub-resolv.conf, and then systemctl restart NetworkManager.service would do it. Maybe you also have to change /etc/NetworkManager/NetworkManager.conf before that. For details, see NetworkManager.conf manual page on options dns and rc-manager.

#Debian #systemd