Yeah, I gathered maybe the pieces were too big right now for them to ingest. They keep trying to eat them and spit them back out each time. One of the three will carry around a piece in its mouth for a while, look at me and spit it out.
So far, two of the three are eating flakes great. The third fish hasn't eaten a thing since he was put into his tank two days ago. He's making bubble nests though. Ha!