He may have some nerve damage – possibly the nerves weren’t working and started working again. It could also be arthritis, even though he is young, or something related to the injury. It may be behavioral – he does it when he wants out and it’s stress related. I would try some different perches – maybe a flat perch – in case the perch he sits on is causing pain. There is a product called Vet wrap that can be used to wrap around perches. It keeps them from being as hard but also offers some texture so he can still grip. Since he can’t chew on things like a parrot can, you might try a soft material to cover the perch, but it needs to be something he can’t get caught in or pull threads from. There are also different types of platforms that are sold for pet birds. I don’t normally recommend these because they can trigger hormones and cause egg laying in a female bird, but if you know he is a male, a platform might be good for him.
Thank you for asking Lafeber,