hoa wants to charge me a fee because i wfh??

just closed on my first house a few weeks ago. the hoa president saw me working on my laptop on my patio and asked what i do. told him i work from home full time.

​today i got a warning letter saying i need to pay a $50 monthly fee for running a home business. i literally just answer emails for a company, no clients ever come to my house. is this normal or are they just trying to scam me? feeling so much buyers remorse right now tbh.