Xfi Gateway user interface changed to Netgear interface

So I'm setting up an access point from an Xfi gateway using a Netgear R6220 wifi router. I don't really know what I'm doing but I'm pretty decent at researching and finding my way around stuff. Anyway, I put the modem in bridge mode and changed a couple of settings and went ahead poking around the Netgear access point after I got it working. I changed a DHCP setting (I think I disabled it) and my wifi stopped connecting to the internet which was weird because afaik, you're supposed to turn off something to do with DHCP in the access point so that you don't end up double NAT'ting your setup. Okay, so since that happened, I tried to get back into the modem without hardlining into it since its a pita but I couldn't get into without doing so. Here's the weird thing ( I think? idk maybe its normal): so I plug directly from Xfi gateway (newer hardware) and I run ipconfig cuz the original ip isn't getting me into admin settings and surprising all get out, the Xfinity Gateway admin user interface has now changed to the Netgear R6220 interface that I had JUST been tinkering with! Now, I'm thinking if I ever want to get the Xfi back to where it was, I'll have to nuke everything and start from scratch, but I guess that's no big deal. If everything stays functioning properly, I won't change it back. Can someone tell me what happened? Is that supposed to happen? And why wasn't I able to access the modem itself from inside the access point? From what I read online, that should have been possible. Well, thanks for reading my report.