Apple Watch Ultra 2 not recording heart rate during sleep after iOS 26 update

I updated my watch to watchOS 26 and I restarted both the phone in the watch. I have checked to make sure Bluetooth is on and neither phone or watch is in airplane mode and they are connected. Bluetooth is on in both cases.Both are well charged. I do get breathing disturbances and sleep tracking information, but no heart rate information after waking, the heart rate begin begins recording again.

[Re-Titled by Moderator]

Original Title: my Apple Watch Ultra 2 stopped recording heart rate during sleep after I updated my phone to iOS 26.