Sometimes if you put in too many at once in their small space it can stress them out. There busy looking all over and around at them. As he gets older it will probably change.
Also I'm sure someone with vield experience will chime in but I believe you should dust with plain calcium as a supplement and dust with multi vitamins once a month, not at each feeding.
What kind of enclosure do you have and size? glass, mesh? and what lighting do you use?