Apple Watch only turns on when on charger and then stuck on Apple logo

Hi everyone,

I'm wondering if anyone had the same issue than me recently (see the subject) and was able find a solution. The issue started when after charging my watch, I noticed that the battery went from ~95% to 1% in a matter of 2 minutes and since then the watch is down. I tried the usual things that you can find on Apple's support website (reboot, unlink with my phone, etc.) without success.

FYI, I have the Apple Watch Series 6 with the latest version at the time of watch os (9.0).

Thanks for your help,