this is a major problem across the series sadly, some cases are bad enough to warrant a replacement others are bad but expected to be fixed in coming updates and a fair few now are starting to report the latest updates helping.
what kind of battery life do you experience, high, medium or low power settings ? Screen on Time?
just to get a general idea.
I've had to opt it for replacements of my 3x S21U 512/16 models based on advice from Samsung but I also have a few other issues with mine including very poor performance compared to others with the same model or even the ones below.