Tootfinder

so
very
frustrating
#Gnome #Evolution how is this even possible? Fresh #Debian13 install, launched, added my google workspace, read and answered email, browsed calendar, really nice, but the VERY NEXT MORNING suddenly tossed into OAuth2-is-missing, step through the 'wizard' and it always ends with the same heartache, are you trying sign in? and then…
Mail authentication (shown) gives a URL to a page, Make sure you trust Gnome (4 perms already granted, Google console agrees) but in Firefox that URL asks to confirm and then reverts to google.com. In the minibrowser, it gets to "Requesting access token, please wait"
And wait you do.
How is this even POSSIBLE? What could cause it to (a) drop an OAuth2 overnight that had been in use for a day and (b) subsequently give a URL that does not result in an access token. I removed permissions on the Google side, but same results. Reinstalled Evolution, no change
yes, I checked gitlab.gnome.org

Found an obscure hint that perhaps instead of authenticating through #Evolution I should instead authenticate through the #Gnome settings for attached accounts, so I tried that approach, this time it asks for far more permissions (8 in all) but, you guessed it, a classic Sam Beckett "No Answer" and the terse response, "timed out".
So the app doesn't matter. The browser doesn't matter. The account or any legacy cruft doesn't matter.
Does this leave as the only explanation that perhaps Google no longer provides OAuth2 tokens? Surely that would be all over the news if true, but I'm running out of local culprits. Also Emacs inability to authenticate Mastodon suggests its neither google nor Debian per se? Maybe I should spend my time more productively slamming a car door on my fingers?
I have a dread feeling wiping the laptop and carefully reinstalling from scratch will not work.