Comments refuse to load under any video now when logged into an account I viewed my Google activity for. It is not an extension issue as it still persists when I disable all of them, and my other YouTube accounts can view comments normally. It's only happening for one account.
Just happened to me. Cleared the cache, reset browser, only happened to one account. I presume that account, somehow, got blacklisted by YouTube - someone probably was offended by something I wrote and reported me. (I don't troll or act nasty, but the last thing I posted was on a science related channel disagreeing with someone - who was really nasty).