help with HOA issue

I am a homeowner in Montgomery County in MD. Recently the Management of our HOA is getting nasty on me. For example, I have a Registered Living Unit (RLU) in my house permitted by county. The former management had no problem with it. But the new one told me that it is violation to the community code for dividing the house. Does HOA have any right again my RLU (also called "in-law" suite) which has been permitted by the County? What should I do?

Thank you very much for your experience or help