Wifi Problems

I have a Cox Panoramic Wifi/Modem/Router which is now bridged to a TP-Link Router and my Network. The reason I don't just use the Cox Wifi as a router is that I have multiple devices. I also have a Home Security System which I can access via my Cell and Camera App. Problem is this; I use to be able to access these apps outside my immediate network range without any problem but recently I have encountered trouble spots without coverage even though I can use mobile networks. My question is can I dispense with the TP-Link Router and just use the Cox Wifi as a modem and router running through a Gigabyte Switch for devices?