I have a bit of a different shouilder injury history.
Started with separation of both AC joints, and then a sublaxation in my right shoulder from hockey.
Although I havent had my MRI done yet it appears I got away without tearing anything due to “looseness” in the joint with regards to how the humerous sits.
But post injury (subluxed in early December), I found either to inflammation or due to scar tissue in the joint that I was experiencing lack of ROM and/or that the shoulder joint wasnt moving freely.
So what I have been doing is wedging a tennis ball between the back of my shoulder and the wall and manipulating the posterior side of the labrum to keep its elasticity and to also break up any other restrictive issues. Works like a charm. I end up sleeping on my side so when I wake up it feels like the joint is compressed togeather. After 20-30 seconds of massaging the labrum with the tennis ball the shoulder movement is essentially unrestricted and any pain has been removed.
Not saying this will totally remove your shoulder issue, but I think its worth a shot.
Best of luck.
Ohhh and before I forget I also got deep tissue massage on my traps, pec major, and bicep on the injured side. Any tension in those muscles will cause the shoulder to line up shitty. After those sessions the joint instantly tracks better.