@Ecki-D. @Brad_Olwin Some updates. The watch has been stopping the HR tracking at night, at different times and for different durations, almost every day. But it always recovers and continues reading. I thought it could be wrong contact with the skin, but I don’t think it is the issue after tightening it more. Also, I rebooted it yesterday, and it occurred again. I wouldn’t care much if it is for a short time, but then the sleeping times are totally wrong, because it seems that the sleep time stops when that happen, if it recovers, it doesn’t count it anymore.
And today, without any interaction with the watch, I noticed that the watch face was the default one. It has lost the one I installed and configured. The software version is still the same. Any ideas? Is it also a known issue? Thank you in advance!