Damn, I really wish I could offer more help beyond ensuring drivers are set up correctly for NVIDIA. I mean, you could also check the power profile too, using something like cpupower-gui to see if it’s in power saving mode. I suppose you could also close other applications to see if one of them is interfering, since you said Firefox may have something to do with it. I suppose it’s possible Snap has something to do with it too.

You said this happens during Elder Scrolls Online, right? Maybe have her close the game’s launcher while the game is running. In my case, I noticed jittery performance in everything, including moving the cursor, until I closed the launcher. May or may not be the issue, but it does sound similar to what happens to me when I leave that game’s launcher open.

I made the switch back in 2020 when I learned how much Proton had improved Linux gaming. I tried it out of curiosity to see if I could make it work for me, and after a week, I had gotten settled. Most of my games worked, some right away, some with tweaking. Some didn’t work at all.

Fast forward to 2025, and now those few games that didn’t work (I wish I remembered which ones they were) do, and I almost never have to do any tweaking to make games work. I’m so used to the way my distribution works that going back to Windows for anything is jarring. I bought a used ThinkPad a while back, and the previous owner “helpfully” installed Windows 11 on it for me (which I promptly wiped and installed Arch Linux, later Debian onto). That was the most I used Windows 11 (about 5 minutes, to make sure the machine worked). I am glad I do not have to use it on my own machines.

I recall another recent time where I set up Windows 10 on a laptop for a friend. It was… not a pleasant experience for me. Again, I was glad I didn’t have to use it.

Linux isn’t ready for everyone, but it sure as hell is ready for me. It was ready for me years ago.