Security System Kicks off WIFI Constantly

Hey All, I'm having issues with my camera system that works off the Xfinity modem. Once it connects to the wifi it works, after 5 minutes it gets kicked off and I have to restart my router. Been trying to speak with a live agent for a technician to come out for a week now but to no avail. Once I restart my modem from my browser and from the automated service it works. Then when I check my app again midday or so it starts all over kicking me off. I was told it has to do with the ports on my modem. Might have to be opened or might something be blocking the cameras from staying online. It almost sounds like it changes IP every time. Can anyone help me?