For some days I have an issue with playing YouTube videos in Mozilla android browser: videos appear as if they were enlarged several times, and I only see a top left corner of the video in low resolution. Full-screen mode, "view for PC" browser option did not change it. I tried reinstalling app, also installed Firefox nightly - the issue remained. On the other hand, videos on other websites, YouTube in chromium based browsers, Firefox on other devices do not have this issue. What could it be?