Series 3 Apple Watch keeps shutting off

I had never had any problem with my Apple Watch (Series 3) since I bought it in April 2020, but for the past 11 days it has kept shutting off by itself, up to 30 times a day and whether I am running, swimming or doing nothing… I have tried everything (update, erase, unpair, …). I see many people have the same issue but so far nothing seems to really work to fix this from what I can read... Has anyone actually been able to fix this?