Earlier quoted context omitted.
The YouTube web app is so full of bugs it's almost unusable on a phone. Comments also disappear regularly on all platforms...
I can only navigate to a video by long-pressing, copying the URL and pasting it into the URL bar, otherwise I get a meaningless "something went wrong" type error message. Mobile Safari, no content blockers, not logged into a Google account. After almost two decades of making the website worse they finally succeeded in breaking "clicking a video". I wonder what the hotshots at Alphabet manage to break next :o)
Suspicion: they’ve fingerprinted me hard and know I have premium but like to watch occasionally from Safari private (with content blockers) and don’t hassle me.
Mainly suspect this given lack of anti-adblocking symptoms.