Suddenly can't login to Youtube.com

At one point earlier this week, I had to sign out of all but one of my google accounts to get a link for a remote meeting to work. Afterward, when I visited youtube, it logged me in under that google account, which is not the one I use for browsing on my own time; I logged out, then, when I tried to log in under the proper account, google/youtube thought erroneously that I had set a passkey, and it and my password manager fought. I fixed the conflict (deleted the unset passkey). Then Youtube stopped letting me log in; no matter what, I get sent to www.youtube.com/oops Initially, this error effected youtube login on all every browser I use. Clearing the cache and history on those, after having fixed the password issue, fixed the problem on them. Firefox, however, is refusing every fix. I have cleared the cache, the history, going back to 'Everything.' I uninstalled and reinstalled the browser. I have disabled all add-ons and enhanced tracking. I have gone into the advanced configuration settings for firefox and deleted the cookie files for my profile. Youtube and Google are ON my security whitelist. I've tried "forget about this site." I've tried private browsing after first clearing the cache and history, "forget about this site", and after deleting the cookie sqfiles. It has been days, and I am going in circles! Can anyone please help me?