I've upgraded to Fedora 38 from 37 and noticed that when my computer is inactive for exactly 30 seconds, the monitors go into power saving mode (presumably because the graphics card (Nvidia RTX 2060, 530.30.02 driver) doesn't provide a signal any more). I checked the usual energy saving dials in Gnome (X11), but couldn't find anything obvious (in fact, I turned off everything that would send the monitors to a sleep).
Where else could I look to avoid the monitors from turning off?
I narrowed down the problem. The issue only occurs after the computer woke up from hibernate. When it actually turns off after 30s of inactivity, there is no log entry.
I also noticed that one of the screens doesn't completely switch off when in hibernate which tells me that hibernate doesn't really work. I also noticed plenty of log entries during the supposed hibernation which means the system was actually running. This issue also doesn't present itself when the system is booted up without prior hibernation.
There is a log entry which may be related, but that occurs during the hibernation (again, which isn't actually happening as per above):
gnome-shell: segfault at 1 ip 00007fb85595c9ac sp 00007ffc43e28d10 error 4 in libnvidia-glcore.so.530.30.02[7fb854800000+28e5000] likely on CPU 1 (core 1, socket 0)