Hello @lestep, I would like to add my welcome to Connect along with @tillysam and others. Tapering off prednisone while managing your PMR symptoms can be difficult since there is no one solution that fits all. My rheumatologist told me that I needed to listen or pay attention to my body when it comes to tapering off of prednisone and to go very slowly when needed. He had me keep a daily log with my level of pain when I first got up along with the dose of prednisone for that day. A drop from 20 mg to 10 mg sounds like too big too soon but each of us are different. Here's some information on the topic that might help you discuss tapering slowly with your rheumatologist.

"How do you taper prednisone for PMR?
Tapering once remission is achieved (following initial and relapse therapies): Taper daily oral prednisone by 1 mg every 4 weeks (or by 1.25 mg decrements using schedules such as 10/7.5 mg alternate days, etc.) until discontinuation given that remission is maintained."
--- 2015 PMR guidelines.pdf - American College of Rheumatology:
https://www.rheumatology.org/Portals/0/Files/2015%20PMR%20guidelines.pdf