PC for some reason stops rendering after a given time

After using Blender for over two years now, mostly on my old laptop, it suddenly occurs that it just stops rendering after a given time. I recently got a new computer (with the GeForce RTX 3080 graphics card) and it’s doing the same thing. I think the problem started when I started using Blender 2.9, so my best guess is that some default settings might have changed? Or do you think something’s wrong with my file? I can’t see any reason why it might be crashing. I also changed my power settings so my PC never turns off; that doesn’t change anything though. I haven’t quite figured out yet when exactly it’s quitting (it closes Blender too, which suggests it just crashes, but why would it do that?), but this last session it rendered out 63 frames before it stopped and closed the app (because obviously it’s super fast now).
Does anybody know what might be wrong or where/how I could find out how to fix this problem?
Thanks in advance!

have you tested it on 2.91 beta?
Cos it maybe bug with OptiX on Nvidia

No, I’m using Blender 2.90.1. Do you mean that I should try out 2.91 or that 2.91 is the problematic version? I just checked, and it appears to me that it isn’t out yet, or is it? Either way, if it’s a bug, how would I fix this? Should I use an earlier version of Blender? I don’t know a lot about all of that technical stuff.
Edit: Also, I’m using CUDA, I just checked in my preferences. To be honest I don’t even know what that means, but I’m using that, not OptiX.

Have you checked to see if there are any crash logs (normally in C:\Users[your username]\AppData\Local\Temp\blender.crash.txt)?

Sorry for misunderstood, I meant try to use 2.91 which in beta now, they have fixed some OptiX bug there, maybe it solve your problem, if not then need to investigate deeper.
2.91.0 beta here