I asked a similar question a couple of weeks ago.
My watch randomly decides to not count steps or measure heart rate. Sometimes doing a reset or turning it off helps, but that’s not the case today.
Whatever I do doesn’t seem to help. The sensor on the back of the watch isn’t blinking green, which indicates a hardware problem.
The watch is updated (the latest update isn’t available yet).
I can connect and update via my PC later today.
Are there any other options I’m missing?
I’ll contact customer support since I still have warranty, but I don’t really want to go through the hassle.