Heart rate during sleep don't show in Health App

I've tried also a reset and all the things recommended, but nothing happens. The fact is that during the day the heart rate data appears in the Health App, but at night-nothing. Talked yesterday with Apple and the recommendation was to unpair and set up as new watch, not restoring from backup, which may be corrupted. Did that, now monitoring the situation. If the problem persists, the watch should be replaced.

Did a restore 9 days ago, set up as new. Everything was fine until last night when the problem reappeared. I will go to Apple service to replace the watch.