I was diagnosed with PMR and perhaps your Dr is correct about being on prednisone. I was taking the dreaded prednisone from Dec 2015 for about 2 years. Then I was declared ok due to blood tests being in normal range. BUT, August 2022 I developed LGA [GCA] . Perhaps my Dr should have ordered regular blood tests during that period between PMR and LGA .
So am sorry to cast doubt about for you with my experiences. Now I am still on prednisone[6mg] and have to live with possibility of reoccurrence of symptoms and even blindness. I should add that during this time of LGA I have had no symptoms of PMR but maybe the prednisone dose is hiding it.