No good at all.
That's a quick drop from 20mg down to 5mg in only five months. I started prednisolone two months earlier than you and am only down to 6.5mg so far, following the recommended reduction schedule. From what I see on this forum, the thing most likely to bring on a flare is reducing too quickly or by too much at a time. Reduce by no more than 10% of the dose each time is a warning often given. Were you just reducing too quickly do you think?

I have not had any guidance for reducing prednisone while taking Kevzara. I do know you slowly taper off prednisone and the Kevzara may reduce pain while tapering. I believe it works differently for each person and may take a few months to help. Others say they get pain relief from the first dose. I plan starting it soon after a couple of procedures. Your taper is so fast I am not surprised you have had difficulty. I have so much osteo arthritis pain in winter it is hard to tell what is PMR and what is arthritis. Hoping we all are pain free sooner than later.

Sorry, no experience with Kezvara. My story in brief: Diagnosed with PMR in August. Started pred at 25 mgs. in the morning. No help. Bumped to 25. No help. BUT, then I learned that people were splitting doses, which my docs sort of reluctantly approved. Half in morning and half at night gave me huge relief right away the next day. Been tapering by 2 mgs every two weeks since then. Now down to 12 per day and will slow down further by tapering by one meg per month soon. So far so good. Following this helpful thread, everybody seems to agree a very, very slow taper is best. Good luck!

That's a fairly fast drop in prednisone dosing.