residence renewal (& address change)

Greetings... I’m a US citizens who has lived in Brussels about 11 years. It’s time to renew my 5-year residence card (titre de séjour) in Ixelles. Since getting the 5-year permit, I changed from being a full-time employee with a work permit, to a self-employed consultant (with a steady contract) doing business as an SPRL company. So, if anyone has danced through this minefield before, and can flag any problems, I welcome your experience.

Complicating things a bit, I filed to change to my address more than a year ago, dutiful submitted paper and such to the commune, and twice filled out the papers requested by the police. But I recently learned that the commune didn’t record the change of address for some reason. So, if you’ve faced that problem before and can point out any pitfalls to watch out for, thanks for any guidance.