I've just made a remark on another thread about the same theme...
When a cham gets aggressive about you removing him form his cage, that is not always a bad sign. It could indicate that he is content in his cage, and has become territorial about it - meaning he would resent intruders (that's you) into his cage.
When a chameleon is over eager to get out of his cage (i.e. when he rushes to you when you open the door, and is happy to climb onto you to get out of the cage), some people mistake this for their cham being friendly, but in actual fact the cham is unhappy inside the cage due to something being wrong with the set up, and it is simply eager to escape from there.
You said that you haven't changed a thing - it's possible that he has just become very used to his surroundings, and is quite happy in the cage. He may just want to be left alone. As they get older they certainly get more territorial, whereas babies are usually quite submissive when it comes to handling.
As I said in the other post: the only time you really
need to handle a cham is to take them to an outside enclosure to get some natural sunlight, to do regular health check-ups (once or twice a month) or to take it to the vet.
Try to start hand-feeding him if you want more physical interaction with him. Eventually he might learn not to consider you as an intruder, but rather a provider, and he may even let you handle him again.
If he starts showing other signs of odd behaviour (change in eating habits, not defecating, closing eyes, walking on the ground) perhaps there is some sort of health problem, and in that case you'll need to provide some more information about how your cham is being kept. Use this stick as a guideline for what information you need to provide:
https://www.chameleonforums.com/how-ask-help-66/
