[Concern] When I stretch my left arm out straight, I feel pain. What kind of exercise would be good for this?

I have been swimming for a long time, and a long time ago I injured my left shoulder so badly that I couldn't move it at all. I received treatment for over a year, and eventually, when I was about to give up and think I had to live with it as it was, I nearly fully recovered. I have regained over 95% of my movement.

Recently, I experienced pain in my left shoulder again during swimming, but this time there is no issue with other movements. The pain occurs when I raise my arm sideways from a position of more than 90 degrees to 110 degrees.

There is pain when passing through the Dosa area. The X-ray shows no issues, but a certain level of pain persists beyond the hindal. I am wondering if there is a way to improve this.