Exactly, this! uBlock Origins will block upwards of thousands of ads/trackers/whatever from YouTube. After it hits about 50k+, it'll start to act strangely. At that point I just refresh the video and it all goes away. I think this happens when YouTube changes something cached in the browser, which was originally not blocked by uBO, even when uBO might have been updated to block the new stuff. I have uBO on auto-update for this reason. Whenever I notice shit not working, F5 FTW!