My vivoactive 4S recently started regularly crashing.
It spontaneously goes into Assistance, then when I try to ‘x’ out of it, it goes to the next screen and if I try to ‘x’ out of that it shuts off. If I do nothing it also shuts off.
This happens periodically but is consistently triggered by me opening the main menu. Although it mostly powers back on, it sometimes takes a full day.