wireles xi

I was convinced by xfinity to upgrade both my wired dvr and wired x1 box when I started losing channels.  Thet sent me 2 wireless xi6 boxes one which worked and the other froze on the welcome screen.  The working box constantly shuts down, freezes and drops out.  Why can't I keep my wired connection?  I was on the phone for 2 hours trying to get help.  The AI assistant is useless.   Does xfinity no longer provide and support wired boxes.