Since August 28th in Fort Lauderdale, Apples Airport Extreme became incompatible with the Comcast network. There IS NOT a resolution to this incompatibility. Certain trained support agents have been able to offer a temporary connection. Most support agents fail miserabley & cannot provide whatever knowledge the experienced agents apparently do have. This is a a complete Comcast FAIL, AT&T fiber is the ONLY choice left.
Exactly what do you mean by "incompatible with Comcast"? Mind you the last Airport Extreme (Generation 6) was released in 2013 and Apple isn't even making them anymore. I stopped using mine in 2018 when I got my ASUS RT-AC88U router, although I did use it intermittently as a wireless access point only with success.