Xfinity, can we please get an update that supports Rock Space Extenders?

Extender: rockspace 750Mbps WiFi Range Extender (RSD0607)

My Xfinity 1GB router (the white one) isn't working with extenders. I connected it with WPS, it's connected but it can't get the IP address. After about 5 mintues the extender will lose connection to the router since the IP address can't be retrived and you have to press the WPS button again. Can we please get a fix through a router update please?

Also note, I've been also having problems with my Gen 2 Chromecast device. My Chromecast just disconnects from the router and won't connect ever again.

The router needs fixes/updates when it comes to accessories. The router just does not like them at all.