I haven't taken any of the Covid shots and still came down with PMR. For one, I had a terrible reaction to a flu shot years ago Secondly, having fibromyalgia, I stay away from ways of getting an infection or cold. People congregating for a shot who may already have Covid wasn't something I wanted to risk. Now with most of those getting it and being hospitalized for Covid, I'm glad I didn't go that route.
I am not arguing the shots triggering PMR, however. Fibromyalgia, another rheumatic disorder can be triggered by trauma, as mine was. I'm just sharing my experience.