WiFi extender

@allthatglam11 Welcome to our community forum! Thank you for reaching out so we can answer your questions about your upstairs TV staying connected to the internet. While I can help with networking on Xfinity equipment, I would recommend reaching out to TP-Link for detailed instructions on setting up the WiFi Extender.

Does your extender have an ethernet port to allow you to connect the TV with an ethernet cable? This will give you a more stable connection while you stream video, as long as your extender maintains a strong connection to your modem. 

Did you buy an extender that matches your gateway, meaning if your gateway is tri-band, did you get a tri-band repeater?  You should have left it tri-band.  by eliminating the other bands, you forced the extender to use a single band for data and backhaul, which will have a negative impact on performance.  Your TP-Link should set it self up automatically using WPS on both the gateway and the extender.  It will then adjust it's settings to give the best performance.  Your extender and gateway should be in the same room when doing this...and after setup, move the extender to the location you want it in.Be aware that if your extender is in a dead spot, then you will have to move it. Dead spots can happen when signals propagate through floors and walls which can cause standing waves where the signals cancel each other out, resulting in very weak to no signal in that area.  You may well have to experiment with changing the location of both the gateway and the extender.  Your gateway should be more or less centrally located in the home, as high up as possible, and not near large metal objects such as cabinets, shelves, etc which can have a negative effect on signals.    You can download an app to your phone that will allow you to monitor the individual bands, their channels, and their signal strength.