Nighty

Firstly its my first post, Hi everyone I have an African grey its turning 2 years old next month. Quick run down the bird was perfectly normally around 7 months ago we swapped him into a bigger cage, which one day he dropped and broke most of the feathers from his wing, A vet pulled the broken feathers from him, few months later he was up and flying again. about 1 month later he broke them again inside the cage. The growing process of these feathers this time around has been very slow. What I'm worried about is that the feathers on his chest throughout the last month, have been messy, all over the place (picture attached). For the last few days the feathers on his tail haven't looked right, they looked like they were 'stuck' together as such, can't explain. This morning he pulled quite a few feathers from his tail was quite a mess. Should I be worried is there something wrong with him? He spends at least 10 hours a day sleep, he spends at least 6 / 7 hours of the day outside of his cage on his play stand our playing with us. He talks, sings, whistles seem normal to me. Thanks, Any help more then welcomed. Elvio