Try slowing down and engaging the muscles. Think about what you’re doing as opposed to just pulling yourself up. Sounds silly I know because it’s called a pull up lol.
To fix imbalances and weakness’ in movement you have to break it down and identify the weakest part and work forward from there (movement screening). Start doing pull ups with banded assistance for example, focus on what you’re doing.
Id also probably go to a physio and get them to take a look. But likely it’s bad habits that have been trained in. See it all the time with people who don’t know how to lift then couple years later they can’t fix it because they have trained to move like that and they won’t drop the weight because they have ego and they never fix it.