I'm experiencing an issue with Wifi with the XB6-A router. My issue is , instead of running LAN line through the house for RJ45 connectivity, i purchased an Ethernet over power switch ( the kind you plugin to a power outlet in your house and have Internet bandwith through the wirering of you house)
Everything seemed to be working ok at first but 30 to 40 minutes later, Wi-Fi corverage stopped working while LAN connectivity continues to work ok. I though something was wong wuth the router, so, called Comcast to have it replaced and they came in to get the new router installed and after they left the same issue recurs. So I decided to test unpluging the TP-Link 1200 Mbps that I purchased and long behold the Wifi connectivity re-established. I'm not sure what interference between the Modem and the TP-Link that is causing that interference.