Definitely a weird one. The search dropdown in AP Payment Entry use to sort by VendorName in 10.1. After an upgrade to 10.2, this now sorts by VendorID:
I’ve searched all over and only found a post by myself in 2020 asking if these can be sorted somehow. Hate to beat a dead horse, but uh… ya, anyone found a way?
Something like below in the Load event worked for me for a UD form - not sure about AP entry. You may need to change the dataset or the field but it’s a good start: