Hello @theref, Welcome to Connect. So sorry to hear you having PMR like pain that moves around. There are many conditions that mimic PMR and I think that's the reason it's so hard to diagnose. I've had PMR twice and while the pain would sometimes be worse in the shoulders or legs, it really wasn't moving around randomly.

@lexaprobiotic recently started another discussion that sounds similar to what you describe here - Undiagnosed Autoimmune Disease - No one will listen to me: https://connect.mayoclinic.org/discussion/undiagnosed-autoimmune-disease-no-one-will-listen-to-me/. I posted the following information in her discussion that might also be relevant for you.

"People with palindromic rheumatism usually have no symptoms between attacks. This is different from other types of inflammatory arthritis, such as rheumatoid arthritis, as people with these conditions will have joint problems most of the time.

During an attack of palindromic rheumatism, the joints involved – and the tendons and area around them – will feel painful and stiff, and may look swollen. They might also feel tender and hot, and the skin over your joints may look red."
— What is palindromic rheumatism?: https://www.versusarthritis.org/about-arthritis/conditions/palindromic-rheumatism/

Does any of this sound familiar to you? It might be worth discussing with your doctor and possibly getting a referral to a rheumatologist/specialist.