as #26 stated, many selective schools don’t accept (or accept at a minimal level) AP, IB, DE for credit purposes. They want you to attend their courses taught by their professors (yes I know it’s a way to get more tuition), but at a certain level of thought, it makes some sense. hopefully the class you take in college is deeper than the class you took in HS. At highly selective schools they better be or what’s the point?
Anecdotally, S took 8 of 9 APs offered in HS. DId well in all of them. Only one was allowed to place out of a core requirement (had to have a 5 on the exam). Had other 5s, but they didn’t count. At first that didn’t sit well with him (or us). But, he actually enjoyed the “repeats” and felt he had a good foundation from HS which helped with a much deeper approach in college. The DEs he took in HS were a complete joke. They were the easiest classes he took by a long shot. Only took 4 because they were a waste of time which is sad because they were held at a local CC.