First, what do you mean you "checked with an agent?" Did you call AA, or are you referring to the PreCheck line monitor at the airport? The folks on the phone won't know anything. Either you can check in online and check your BP, or wait until you get to the airport and have your BP scanned to know if you got PreCheck or not.

As a no-status passenger on AA, it took a few flights after putting in my GE info before qualifying for PreCheck, even though I had been getting it consistently on UA, where I also have status.

Nobody ever said Global Entry guarantees PreCheck. It's possible your AA profile information doesn't match your GE info. Or that the info just hasn't percolated through all the systems yet. Or maybe you're just unlucky. Can't always expect instant gratification.