my streaming service is directed to the chicago market rather than my local market. All indications are the IP address of my router is the problem. I powered down the router for 48 hours hoping it would reestablish the correct IP address. How can this be set to use a local market IP address?
You likely recently received a new / different WAN (public) IP address assignment to your connection from their DHCP server / IP address pool, and the rDNS / geolocation data that is associated with it is now incorrect for you as it previously belonged to someone else that lived in that area. Comcast shuffles blocks of IP addresses around the country all the time. ISP's don't correct this. A third party service does.
If you have a router that has a MAC address cloning feature, you can try cloning a different MAC address in to it. This will force their DHCP server to assign a new / different public IP address to your connection. This may or may not correct the situation. YMMV.