You tube display

So I recently added a youtube extension to block adds on youtube. Shortly afterwards the youtube home screen changed with much larger thumbnails, the viewable screen itself much larger after Ive clicked on a video, no room to see comments and any attempt to wind a video on by dragging the mouse was no longer possible. Ive disabled the add blocker and all other extensions, reinstalled firefox but the problem persists. Tried it on google chrome and safari and its all normal . Hope this is the correct forum…can anybody shed any light as to whats happened?

As an experiment, try creating a second Firefox profile to see if the same problem exists. If it doesn’t then make the profile more like your main profile until you see what caused the problem. Sync can help with transferring information and some settings.

Thanks…but I eventually sorted it by deleting the cache and cookies