Windows 11 runs slowly when FF is open
Since around the time I updated to Windows 11 version 24H2 (which I severely regret doing, but it's too late to revert), my computer runs very slowly for several seconds whenever Firefox is launched or whenever its window is restored from minimized. It also randomly slows down the computer every minute or two for several seconds. The slow down manifests as a very long lag in cursor movements and typing.
The impact is most severe when I am running other programs at the same time, including Outlook and a rather old version of Quicken, but it can be seen even when there are no other programs running.
This happens even in Firefox troubleshoot mode. This happens even after a refresh. I tried deleting my entire Firefox profile. I tried uninstalling Firefox and reinstalling it. I tried reinstalling the two previous versions of Firefox. I tried with hardware acceleration off and on. I tried changing every possible video setting I could find. My video drivers are fully up-to-date, as are my Windows updates and my BIOS. Nothing has helped. The same problem even exists with a brand-new installation of Firefox and a brand-new profile!
Notably, I don't see this issue with either Chrome or Edge. And I don't see it when many other programs are running at the same time without FF, even RAM-hungry and CPU-intensive programs like image and video editing programs. This is specifically a FF issue.
Before updating to Win 11 ver 24H2, FF was running on this computer for years without issues. I can't say the problem started exactly when I installed 24H2, but it seems like it was around then. I have another computer still on 23H2 with the same version of Firefox (and the same versions of Outlook and Quicken) that does not have this issue.
My computer is essentially unusable when Firefox and any other major program are running at the same time. I've tried seeing if the CPU or RAM usage spikes during the slowdown, but since the computer nearly (but not quite) freezes when it happens, I haven't been able to catch it live.
Thank you to anyone who might be able to help. I've had to move to Chrome because of this, and I'm not happy about that.
Ndryshuar