Phone stopped showing heart rate variability
My phone XS and watch 5 used to show heart rate variability but no longer does this for a few months now
Question marked as
Perhaps the heart rate sensors are no longer working. Do the green sensors on the back off the watch light up?
Monitor your heart rate with Apple Watch - Apple Support
If so, the first (and simplest) thing to try if something isn’t working right is to restart your Apple Watch and its paired iPhone. If necessary (device not responding), try a forced restart. Both methods can be found here:
How to restart your Apple Watch - Apple Support
Restart your iPhone - Apple Support
If that doesn't help, the next steps would be to unpair and pair your watch again and restore from the backup just created. This should result in no loss of data. It deletes all temp and corrupted files and re-indexes the file system.
Unpair and erase your Apple Watch - Apple Support
Set up your Apple Watch - Apple Support