Apple Watch 6 constant battery drain

Ho everyone, I bought my Apple Watch 6 at launch and since then it is having a continuous battery drain issue, I have tried to restart it, change the settings and re pairing it to my iPhone but the problem is still there, after I te pair it to my phone the issue goes away for sometimes but it comes again at random, the last time that happened was today where I went to bed with the watch fully charged and after 8 hours of sleep three watch went from 100% to 80%, can someone help me? I have heard that I coul do like an online diagnostic or something like with Apple, I don’t know if it will help, what do you think?