I haven't read harry potter for 20 years, got totally burned out before finishing the series and as you can imagine 14 year old me wasn't exactly very aware of trans issues but here's a few even my thick headed teenage brain found weird:
Bankers are basically jewish caricatures - short goblins with long noses that only care about money
Weird slavery message where Hermione is proven wrong for wanting to free the elves as a lot of them are happy with servitude
Every foreign character is a weird stereotype. I think there was even a Korean character with a chinese name like Chong? There was clearly no concern for portraying anything correctly, just a weak attempt to increase diversity with no effort I guess
There were also a few weird things adjacent to harry potter like how every major character is basically described as alabaster white and she later attempted to hide her bias by saying "I never explicitly said that X was white". Lady, you literally wrote that Hermione was a pale redhead in dozens if not hundreds of pages. I don't care if she's played by a 4 inch tall blue alien, just own up to it and stop gaslighting people.
Also, not a big deal but it always felt weird to me that even the nominally poor family lived a life of luxury. I could tell the person writing never truly knew hardship from the way she wrote the Weasleys. I can't say I have much experience myself but it felt strange how they kept saying a clearly upper middle class family was destitute and made fun of.