Been rereading this series and slowly seeing the problematic elements. It's small things here and there like little to no BIPOC, disabled or LGBT characters though there are a lotore LGBT representation in later books, fatphobic comments,

scapegrace in the later books is transferred to a women's body and is constantly misgendered and sexualised and has constant jokes made ect. 

There are multiple cases of characters who can't speak or move being referred to as a vegetable, a common and offensive insult to disabled people.
Especially in the later books POC characters are referred to as having "skin like chocolate." I'm not black though I know that this is considered offensive.
There'll be other things I've missed but this is what I can currently think of.