Every once in a while either my Gmail stops loading or I get an alert that my iMac can’t connect with iCloud. If I try to reconnect using the official method “forgot your password?” etc. nothing works. No gmail or Apple passwords are recognized and there’s an endless round of alerts.
What works: restarting the computer. I learned this after a lengthy session with Apple support the last time. When it happened again I didn’t remember it right away and dived into the usual morass of attempted sign-ins, until finally I remembered: restart the computer.
And after a few hiccups, everything is back to normal and my new mail loaded.
Always worth trying the simplest thing. Now if only knew what was causing these disconnects in the first place. . . .