Many of the treatments for RA do weaken the immune system - It is important to address vaccinations for influenza, pneumonia, Covid and Shingles. Prednisone use should be minimized but all of these things can be discussed and managed with your rheumatologist

It is a symptom of a poorly controlled immune system.

Not as likely as a real immune problem such as a deficiency of gammaglobulin production, or even a different disease such as lupus. This will require blood testing for these problems. The specific tests can be done at a chemistry lab approved by your insurance or at the health department.