Sometimes when I open different programs on my computer and have firefox open at the same time all my firefox windows will stop fitting to my screen. (See images). Programs that it has happened with is VS code and the built in windows 10 mail app. It usually happens when I have VScode in fullscreen and then pull it down to make it windowed. My setup consists of 2 1920x1080 monitiors and any instance of firefox on either monitor will get this issue at when using VScode or the mail app. Only solution that fixes it is to open a new instance of firefox and drag all my tabs into it. Been on the same setup for 3 years using chrome previously with this never being an issue. Switched to firefox a few months ago and this has happened pretty regularly. Image 1 is when the window is in focus, image 2 is when the window is not in focus. Happy to provide additional information/video of it happening if needed. Thanks!