Slightly worried about my Peeg

So Bullseye is about 8 months old & very, very shy. He doesn't like being held, & he still gets scared whenever my hand is in the cage (even if I'm feeding him his favorite, parsley). But when I used to put him out for floor time, he'd run around like a maniac, wheeking the whole time. It was adorable. Now when I take him out, he runs around a bit, but then prefers to just sit in the corner, occasionally walking around & playing with his toys. He's still eating regularly, & seems okay. And he'll still wheek whenever I give him snacks. I guess I'm just worried if there may be something wrong with him? And if there was, I'm not sure how I'd check on him, since he still seems so frightened of me ): Any help would be appreciated!