

Maybe your GPU is set to a low power mode? I wonder if something like CoreCtrl might help you.
I don’t have this problem on my Debian 12 machines, which both use this browser on XFCE, but they have AMD graphics. Then again, I don’t online game that often, but when I have, I don’t recall any problems.
Incorrect, actually. Firefox for Android uses Gecko like the desktop version, while the iOS version is stuck with WebKit.