Garmin Swim 2 turns off when using GPS

After the last update (I think it was in November 2025), the watch turns off by itself.

I'm testing it every day in Run mode. After 4 or 5 km it turns off.

Important: the battery seems to be fine, because outside of GPS mode it stays charged for more than three days, which was normal since I bought it.

Software Version = 3.10.