Media Encoder/Premiere can't sign in to YouTube channel for auto-uploading of export

I think this was posted here a long time ago, but I can't find a solution. I've signed out of all of the YouTube channels I usually have connected in the export dialog in Premiere, but it's not letting me log in again - I'm getting the message in this screenshot. I've tried changing my system's default browser, and restarting everything, but not getting anywhere. Any help much appreciated, thank you.