After such a long term issue it is difficult to say without doing manual testing.

However, it is likely that there is a deficit post dislocation that wasn't prepared for the amount of activity recently that resulted in a subluxation.

For example, If the dislocation resulted in 50% capacity of the shoulder comple3x, and it was rehab'ed to 75%, and you are completing 80+% activity, naturally there will be a deficit in shoulder integrity