On firefox youtube videos take a long time to load, they’ll play for a bit and then buffer. Without this extension youtube works fine on chrome. I guess this extension is in beta stage, needs to be polished more.

Considering it’s from the same person behind sponsorblock, I’m positive future updates will fix this issue…

Edit: Seems I was using old version, just updated the extension as developer said they’d fixed the above issue in new version. So far so good, now videos are playing fine on firefox…