Rings Don't Update and Heart Rate Sensor Doesn't Work - SE

I have an Apple Watch SE. Earlier today, all of the rings stopped updating on the Watch. Also, when I attempt to manually check heart rate, I see the green lights of the sensors on but my heart rate doesn't register either. Sleep, workout, activity, and other monitoring is similarly not working.

I have tried most of the options mentioned in these forums, short of factory resetting the phone or Watch. I have restarted both devices (individually and at the same time, restarting them in different order, and force restarting them). I have unpaired and re-paired the Watch, restoring from backup.

I have all of the proper settings turned on, and the watch was working fine before it abruptly stopped working (in other words, I had the settings all proper and functional for over a year and half before it suddenly stopped working so it's nothing like "Wrist Detection" or the various tracking settings not being active). It's also not related to the watch's location on my arm, since that also has not changed.

Any ideas what I can do to repair this issue, short of wiping the whole thing. Thank you.