Issues with wifi frame

For Christmas I received a wifi frame which is supposed to connect to my wifi network via my Nighthawk router. The frame is not compatible with 5G so I  connected it to the non 5G network setting. I set it up and for a couple weeks it worked fine albeit it would lose and regain wifi connection ever so often. Then suddenly it wouldn't connect at all. 

Of course I contacted the manufacturer and went through the endless process of resetting routers, cell phones and the frame itself. I also changed location of the frame to not be near any other device. Nothing is working. 

They say I have to contact Xfinity and ask if a security or network setting may be blocking the connection. Please xfinity experts, help me.