Modem showing different IP than Xfi online portal
So i have been on the phone with tech support for an hour and a half, which i thank the lady for bearing with me as i got more and more frustrated, but unfortunately she wasn't able to fix my issue, and Comcast does not pass customers onto higher tier support, they use the Tier 1 phone support as intermediaries, meaning i cannot directly talk to Tier 2-5 support, who may be able to fully explain my issue or figure out how to resolve it on their end, considering the issue is appearing on the main network side.
My issue is this,
My Internal IP (preferred ip) is 10.0.0.89, it shows this as being my ip address both via IP config and the GUI for the modem logged in via 10.0.0.1. When I log in to the Xfi Portal (https://internet.xfinity.com/connect) and look at my Device it shows my Internal IP as 169.254.122.130. So any time i try and modify my network to change settings for my computer (named MainPC on Xfi), and use the drop down menu to see my device which shows up as MainPC and set the changes, when i click to apply the changes it says my IP Address is not within the range, which is 10.0.0.2-10.0.0.253. My Internal IP Address is within that range, my modem shows me as within that range, but the Xfi portal that i am forced to use does not recognize me as being within that range, even tho it automatically populates on the list in the drop down as an option.
Currently using only Comcast provided equipment, Directly plugged into the Modem/Router combo.
TL;DR Comcast is currently showing me as two different IP Address's on their Modem and the Xfi application, which is causing issues.