What you may be interpreting as him not liking the other birds is more likely him trying to communicate with them. Conures are very loud in their flocks in the wild. It’s just their nature. When he is with other birds, he is exhibiting vocal flock behavior. And it’s natural to want to be the loudest. When he screams is he looking at the other birds or is he clinging to the side of the cage with his back to them? If he is watching them and looking at each bird, he is just joining in. If he is trying to avoid looking, then yes, he is scared, but it doesn’t mean he hates them. He just needs time to get to know the other birds and find his place in the flock. If you keep taking him back and forth, he isn’t going to learn to accept the other birds and they aren’t going to accept him. While they may not get along outside of the cage, most birds can get along in the same room in their respective cages. It’s also important that each bird has a wall behind him, where he can feel safe and not feel like another bird or predator can approach him from all sides. Try Paulie in a spot where he only has one other bird next to him and not on either side of him. This can help him to settle in better and not feel like he is on guard.
Thank you for Asking Lafeber,