My Danny (cockatiel) was in the house almost a year before he would voluntarilly come over just to chat. He spent 10 years in an abusive home. He needed to learn to trust.
Mr P (sun) was 3 months before he was social.
Sailor just got here. He had a year of trauma in the rescue that he came from. He got the physical attention that he needed, got the food, got time out of the cage, but with all the other rescued birds, just couldn't get much more.
The place he was before, was a hoarding situation. For as much as he was loved, he had to share that love with dozens of other parrots. I have to show him that there is not only love and acceptance here, but that he is a part of it, not just an onlooker yet again.
Give him the time he needs. Let him be the sweetheart that he is hiding behind those feathers. A shy two year old human child takes time to adjust to new situations, and you have a perpetual one.
It will happen if you let him be himself, and not put expectations on his feathered shoulders.