u/Feeling-Working-2820

I bought an iPad M5 pro with nano texture last month.
My only use for it is as a notepad with notes and the Apple Pencil pro.
When using it as such, I don't have any other app opened in the background.
No economy mode, maximum brightness.
As suggested by Apple, I charge up to 80%
But each minute, I lose 1%, it's just crazy. It's actually even a little less than a minute.
At that rate, it feels like the iPad would last me less than 1.5 hours with just me writing stuff.
When I go and check the battery health, it is mentioned 100%.
Is it an obvious issue or is it something about using the pencil or what?
What do you think?
Thanks.
Full disclosure: My iPad fell a few weeks ago but appart from a dent on a corner (where the protective case isn't covering the iPad), it seemed totally fine and the battery issue seemed to be there since day 1 anyway as I remember I was astonished that I had to recharge it pretty quickly, even the first few days.
So I don't think it's related. I wasn't paying much attention because I only started to try and use the iPad more intensively these last 3 days. This is why I only fully realized today that there was a problem.