Hi timo, this is the same issue as Ubuntu 25.10 and using the default desktop environment Gnome 49 with Xorg removed. We are actively working on a permanent solution for users wanting to connect to the virtual display on Gnome 49.
We have an article about this here:
Ubuntu 25.10 Questing Quokka drops Xorg/X11 support, what this means for NoMachine users.
https://kb.nomachine.com/AR10W01330.
The same tips written there for Ubuntu 25 users can apply to your case with Fedora.
If you still need to run virtual sessions, alternative temporary solutions are:
1. Install another desktop environment compatible with X11, such as MATE, KDE Plasma or XFCE.
2. Use an earlier version of GNOME, prior to version 49, which still supports Xorg.
3. Use an earlier version of Fedora.