Have you ever looked into Mast Cell Activation. Here is a guide to review...the symptoms can be all over the map and mast cell issues can look very different from person to person. If you think this might be a clue, I would ask your doctors to run some of the recommended tests...it is critical that you review and follow the procedures for each test (24 hour urine must be handled very carefully by you and the Lab to get accurate results, you gotta dog the Lab to make sure they do it right!).

I have autoimmune issues and after a bad infection 7 years ago (CDiff) my Mast Cells started misbehaving. It took me a few years to figure out and learn about Mast Cell Activation...I have now had all the recommended tests (except bone marrow biopsy) and they found a high level of mast cells in my gi tract. Now I am on alot of the recommended Mast Cell Stabilizers and a low carb/low histamine diet and am doing great...no more joint pain, no heavy drugs or steroids!!
This link will take you to the guide https://www.ehlers-danlos.com/wp-content/uploads/MCAS-Primer-for-the-Gastroenterologist.pdf

or google "primer for mast cell activation syndrome" and select the one on the Ehlers-Danlos website, where you can read the guide for free...

Good Luck
BTW, if it is a Mast Cell Disorder, Mayo has a reputation of not treating MCAS and only Mastocytosis