Angelfish question

[KJoFan]

I recently purchased some juvenile angels (quarter size now) at a local club auction and they have been doing great for the last 3 weeks, eating like pigs etc. The past few days I've noticed one off by itself and kind of clamped up. It comes out when they get fed but doesn't eat. I'm not sure if it's just getting beat out by the more aggressive ones or what. Would those of you with more experience raising angelfish suggest trying to separate it from the rest to see if it eats without competition or what? Any help or guidance is appreciated.

Thanks!