Pale Moon forum

Starting maybe a week ago, Youtube player looks weird compared to Firefox: when I click on cinema mode button, the aspect ratio changes into bizarre one with huge black bars on both sides, with the video itself even looking cropped and in a way maybe smaller than the default view.
Does anyone have the same problem? It's a mess, and watching stuff like displayed in this bizarre way is really annoying.

I do see black on the sides in cinema mode, but the viewing area is larger than the default. The proportions in the video look normal to me. I did not notice that before, since I usually use full screen.

It just doesn't enlarge in any useful way like it does in FF.