I have the same issue, since friday. I make the update thursday : 2.40.38 on race S. HR measures stopped twice around 10-20 minutes until I restart each times.
Yesterday, exactly the same : it stopped around 15-20, i don’t restart.
I decided to reset, yesterday…
This morning, my watch crash I start, twice a cycling activity. On the third attempt, it was entering “safe mode”. It work fine and same problem, HR crash…