Apple Watch Series 9 Battery drain

Apple Watch battery drains to 1% within 3h.

I have an Apple Watch Series 9, I bough it like 5 months ago, running WatchOS 10.3.1 and since 2 days it has been making weird stuff with it's battery life. Battery drains super quick. I had it at 80% at 12:25pm and now it's only 14:55pm and it's at 20%.I am not doing nothing, Im literally wearing it as I did 2 days ago, working from home, doing nothing extraordinary...

I tried resetting to factory settings and pairing it again, the issue is still there.

I checked the battery life, and it says it's at 98%.

Anyone has the same issue? Do you know how to resolve the issue?

Thank You