Noticed this today. Was selling some extra rank 3's. I held down their pictures to see their stats on the selling screen when I saw that they would randomly show different bonuses, sometimes in the thousands. Further, it wasn't based on the type of minion. I had 2 sentinel dogs for sale. One had bonus hitpoints up to 6k, while the other had 2k. Several other monsters had other bonuses listed, all of them despite being completely new from rare shards and not equipped. And some had no bonuses. When checking them in the My Team screen, said bonuses weren't there, of course. Just an odd specific information glitch.