QP stopped talking? Does not appear to be sick

I rescued my QP on June 17th. He did take to me immediately but it took a long time to build trust. He now will let me pick him up, finally will step-up, loves to be scratched and enjoys his time out of the cage. During that earlier time he would talk up a storm, especially when I approached the cage. I feed him twice daily but also leave pellets in food cup all day. Switching to pellets changed his behavior and he has become more active and more tame. However, the only thing he wants to do is go to the top of the cage and rearrange his hanging toys. In early morning when I uncover him he will go to the top of the cage and come down to a side perch, give me a kiss and say "Hello", I give him a treat, and then he goes to rearrangement of toys. When he steps up, from inside the cage I take him to another room and walk around the house. When he gets enough of that he flys back to his cage. Except for the morning "hello" , I rarely hear a peep out of him all day, not even screaming. I know he knows how to talk, but just doesn't want to unless he gets nervous for some reason. Any ideas? Thanks