No, I did have a frozen shoulder on 2019, I had PT for it and haven't been bothered by it since then , it seems that I have been in PT for a lot of things since then, but it works.

It could be medication but Parkinson’s itself can cause redigidty and stiffness I have dyskinesia mainly lower body ( that’s med induced) add the rigidity and stiffness it’s very painful. But their are things that help amantadine and others I would talk to your MDS or Neuro about it. Also you can find some good stretching exercises for your shoulders on You tube if you have internet access I believe you said you did. Simple exercises to help keep
Your shoulders lose. My shoulders lock up from
Time to time ironically while I am exercises mostly I find some simple stretches of my shoulders and arms very helpful. And then a good topical rub . I hope maybe something in there might be helpful
Blessings

I had terrible shoulder pain and could hardly undress myself by the end of the day. My homeopath put me on a course of magnesium and I feel like a new person.

My pain is in my upper arms and elbow area. Not the neck so much. I take Tylenol. And magnesium cream for relief