That worked, thanks. I had to remove ’ --drop-privileges=gvm’ for it to work.
The final changes if it’s useful to anyone were:
sudo nano /etc/systemd/system/gvmd.service
ExecStart=/opt/gvm/sbin/gvmd --osp-vt-update=/opt/gvm/var/run/ospd.sock --port=9390 -a 0.0.0.0
sudo nano /etc/systemd/system/gsad.service
ExecStart=/opt/gvm/sbin/gsad --mlisten=SERVERIP --mport=9390