It can be either. You can have the Main Character adopt the Solution but it didn’t prove to relieve him of his angst. And again you can have the Main Character not adopt the Solution and therefore never relieve his angst. It all depends on what you are trying to say about his/her Inequity.
Hamlet, Lawrence of Arabia and Unforgiven are examples of Change/Bad.
It’s not necessarily a solving of their original problem because you gotta remember the reason your story exists for the Main Character is to provide him Signposts and Journey’s to get him to relieve the problems that are rooted either within himself or between him and his environment. So I don’t think he can ever “solve” a separate problem other than the one he started out with which is tied intrinsically to the rest of the story.