I found a peculiar bug with #firefox and #bottles in #flatpak
If you install Firefox from Flatpak, you can use hardware acceleration no problem. However, if you THEN install Bottles from Flatpak, it auto installs ffmpeg-full 24.08.
However - then Firefox is using this ffmpeg-full for hw accel and breaks video players (other than YouTube), so that you cannot revind. That's because ffmpeg-full is an optional dep of Firefox, but the highest it supports is 23.08. So you have to install also that