A prednisone flare and a PMR flare are almost identical in pain. I generally think most everyone has a prednisone flare when getting below about 7mg and particularly below 5mg. Its true it may restart PMR thats why they start you on MTX or some other anti inflammatory. Some do not have elevated markers with PMR. At least not elevated outside of normal. However unless you had a baseline test before PMR who knows what your normal might be. My thought its a prednisone flare from lack of cortisol. Or adrenal insufficiency. You can experiment with your dosage if you go back up. Go up then try to get back to 3.5 in the first week. Then the only solution is to taper very slow. Try to restart your adrenal system.