Works well on YouTube, but breaks videos on other sites - in this case specifically Teachable courses. I'm not sure if it is something about the video player used (hotmart), but it blocks the player from loading in properly and returns a "Something went wrong" text in place of the video.
Issue was solved through Refreshing in Troubleshoot mode, as using regular Troubleshoot mode, uninstalling the add-on, and deleting browser preference data didn't work either.