Text area when commenting on MR changes is terribly slow on firefox

These last release on firefox, the text area where one can put comment on a given line has become incredibly slow (you can see the letters appearing one by one) and is unusable on mobile it seems to set my CPU to 100% for some reason, I have tested it on several firefox (the latests release of this last 3 month at least), be it on my desktop/laptop/phone and the problem persist. I don't know for other browser, i need to take the time to test