I actually have the Deco AXE5300/XE5300, but it wouldn't show up in the choices for the model.  I just wanted to post this to perhaps help others who are having issues with setup when creating the Wi-Fi network and the light turns red.  I had this issue and I worked on it for hours before Xfinity told me to try a different cable.  I had been trying setup with the provided network cable that came with the router.  I swapped it out for a different ethernet cable and the router instantly changed the status light and the app showed connectivity and the network was created.  I tried all the other tips others were providing in my google search and in this community, but I can't believe the solution was this simple.  If you are having the same issue, try swapping out the network cable and hopefully that works.