Double NAT on my xbox causing me to not have access to servers

Hi there, I recentley purchased a Nighthawk xr500 for my gaming room i'm in the process of building. I plugged it into my cable modem router and it worked great on my xbox one s for about 3 weeks. No issues whatsoever. Until recently, when I logged into minecraft bedrock to play some servers with my friends. Everything was gone. It was stuck loading continuously. To test, I hopped on Call of Duty and I couldn't connect to ANY server in matchmaking. I was confused and I spent about 3 days trying to fix this. Thats when I learned about double NAT. I tried all the tutorials, followed all the steps but nothing worked. I was getting frustrated at this point because I couldn't play. I put my xr500 into ap mode, and that fixed it, except the entire reason I bought the xr500 was because of the geofilter and ping assist. That all went away when I enabled ap mode. I don't want that. I recently spent an hour or so on the phone with netgear. They told me to turn router mode on my modem off. I did so and my NAT was open. But all the servers were still blocked. I wanted to put my modem into bridge mode, but Netgear support wouldn't do it because it was past its 90 day warranty. I called my ISP but since it's a netgear modem they couldn't do it. Now I'm stuck. Do I return my xr500 and use an ethernet cable from my modem to my xbox. Or is there a fix for this. Thanks.