I don't think Firefox has changed what it sends to websites to compose the message, but sometimes mail sites change how they interpret it. I don't have an AOL account so I can't test AOL for myself. (Actually, I started to create a test account, but they demand a mobile number, so never mind.) If you check the address bar, does the URL seem to be included there? It's okay if the special characters like : and / are encoded with % followed by a pair of numbers/letters.