Apple Watch suddenly unpaired and fails to re-pair

Apple Watch SE (currently OS 9.3.1) has been paired to my iPhone 11 (currently OS 16.3.1) and working fine for ages until recently. I received a pop up on my phone saying the phone’s password needed to be updated. I did so through settings. A few hours later my watch screen said I needed to hold it close to my phone, & when I did it started to pair, but failed. Hours of every option I could try, even with apple support on a call. Reset watch, tried pairing from backup, tried pairing from factory reset, even while pairing would be forced to unpair, only to have an error when unpairing. Support remotes into phone and watched all errors. At one point it worked after doing a factory reset, and I was able to pair and use the watch. But a few hours later it did the same thing. Now won’t pair at all. This same scenario happened to two others I know this week. Any word if there is a glitch or bug in latest updates and patches?