I have the regular S10, after I unplug mine the battery goes from 100 to 97 within 10 minutes, after that it seems to be ok, I can get around 5 hours of screen time, still bugs me how fast it drains right when you unplug it
I stopped hoping it would get better and went for the factory reset and so far it has helped. I used smart switch to backup my data then did a factory reset and restored my data after going through setup. I have just lost 1% over an hour and a half of standby.
Just an update now that I have reset my s10+. It has been off charge from 100% for 16h36m and I'm now at 47% left with 4 hours of screen on time. I think it's safe to say the battery issue is now gone 😊