..re: brayozz..
Hard to not assume idiocy when it shows its face without troubleshooting.
All possibilities: including sync between iPhone & Apple Watch. A 1st step
could be use Continuity info to remove Mac & Phone from the equation.
"Nothing to do with the question. Stop assuming that people are idiots.
The AW unlocking feature WAS WORKING before Big Sur." ~ brayozz
Thanks to John Galt's reply, the ideas of troubleshooting are not dead.
Links to Apple Watch and iPhone that I'd assembled toward reply here
have been deleted; but followed similar path to look further, & resolve.
Good luck!🤖💩😜