HELP! Trouble setting up an ASUS RT-AC87U as media bridge to Hitron Modem/Router combo...

I'm a newbie to the whole media bridge game (and this forum), and am in desperate need of some assistance. I have an ASUS RT-AC87U I'm trying to setup as a media bridge for my Xbox one. I currently have a Hitron Cable Modem/Router combo with a 1Gbps down/50 Mbps up, but wirelessly I wasn't getting the speeds I wanted with either the 87U or the combo, so I decided to try a media bridge. However, after disabling DHCP on the Hitron and following the steps to put the 87U in media mode, I'm not...

HELP! Trouble setting up an ASUS RT-AC87U as media bridge to Hitron Modem/Router combo...