google account login

For weeks now, I cannot continue past the initial login field when trying to sign-in to my google account from macOS safari. I type in my email/username hit enter, and the field is immediately covered with the previous prompt. See image below. I do not experience this on any iOS device or other browsers on my Mac. I have not added any new software since this began.

I've tried every variation of privacy/security settings for safari I could think of or find on the interwebs, including the cross-site tracking settings et al. Restarting everything in various order, clearing caches, checking updates, forgotten extensions...everything with everything. Anyone have useful ideas/experience?

Please help me Obi-Wan, you're our only hope.