Double Nat issue for Xbox One

 

I am having a double Nat issue with my Xbox 1. I have the X6 R8000 going to a comcast 1GB's Router in my basement. The X6 has the latest firmware update and I just did a reset of the router. I can not put my Modem/router from Comcast into bridge mode because I will lose my interenet connection for my security system which is also from comcast (X1 quadruple Play so to speak). I did set the X6 to Open Nat in Netgear Genie. Is there another work around or do I have to set my modem into Bridge mode. I did set up a static IP for the Xbox one and have it set up in DMZ mode.