I often like to have 2 browser windows open with multiple tabs going on each window. Recently, however I noticed that whenever I watch a video in full screen mode on one monitor then I switch focus to the second browser window to do other various activities, the video playing on the other monitor will sometimes exit out of full screen mode and continue playing in the original embedded small screen size. So far I've tried disabling all but the most essential extensions, put the theme back to the default mode, made sure my graphics card is fully updated, and even attempted a few setting changes people have recommended for fixing similar issues, but nothing seems to work. As of right now, the only workaround would be to use the picture in a picture mode and put that to full screen, but that isn't ideal as picture in picture mode is set to be "always on top". I could also use a different browser, like Chome on my second monitor which doesn't seem to cause the video to exit full screen mode, but again, I typically prefer to use firefox for most things online. Anyway, I'm now out of ideas on what to try to get firefox to behave in the way I want it to.