Ok, I think you can get rogue blood results
Once, years ago my ESR was 5.
The silly billy nurse smiled and said I must be cured-
Had I taken on the bee sting therapy?
But the next blood I was back doing my ESR thing of mid 30s. I'd had ra for a couple of years by then and I was suss, even then!
And suddenly I wasn't cured after all.
Also
There's a process of inflammation that chews joints. That process in RA means joints get chewed
There's chemistry in that joint that has been set off by time having all that corrupted ra chemistry in there
Even when the ra isn't rushing through your blood, the processes of damage to that joint are now in process.
Thirdly
It might be an infection or something else like a bursar injury.
These things need medical eyes- you know how to access this
I do find the blood tests give a guide. But that's all. Sometimes I've felt awful and bloods pretty good and other times felt ok ish and the ESR /CRP have shot up
I understand a good rheummy does consider test results but considers the patient first
how to be a velvet bulldoser