I second the idea to change to a VNC solution independent of the Gnome login.
To my knowledge, it is not possible to have a VNC Server that interacts with the desktop that is independent of the GNOME login. Since the sole purpose of this machine to act as a physical “monitor” I cannot use something like TigerVNC, unless it were a VNC “scrapping” server which apparently does not exist for Fedora (only Ubuntu).