Internet Connection problems.

I'm at the end of my rope as to what the issue is. So I have one xbox that has the router about a foot away from it and it has no problems streaming shows. But i have my xbox one x about 15 feet as way from it and over the last 2 weeks the connection on it has turned from great to it stops every 10 seconds to buffer the show. What the hell would have to be changed to go to that from doing great?

And before anyone says anything yes I have reset the router, the xbox connection itself, turning it on and off again, the usual troubleshooting stuff.

Both if their network screens in settings are identical but for some reason that 15 foot difference with an open door and everything is causing it to be super slow.