CBK40 and XFINITY - Odd Issues

I set up the CBR40 modem/router (Gateway) using Orbi app.  Went fine. But about one day later, XFINITY-Streaming said my computer was not on the "home network".  (There are certain channels that can only be streamed if on the home network.)  The CBR40 also disappeared from xfinity's list of my devices.  Cable and Internet services were otherwise fine.  My INFINITY account stated that my "Gateway May be Offline."  (which it obviously was not).

An XFINITY support person told me that the MAC address of my CBR40 was already registered with another account with XFINITY??? She asked me to contact the person I bought it from??  I had purchased the CBK40 kit NEW from AMAZON. They could not help me.  

I reset the Orbi CBR40 and redid the install with the Orbi app.  Went fine again. XFINITY listed the CBR40 as one of my devices and recognized my computer as being on the "xfinity home network."  BUT ONE DAY LATER, the same thing happened. [XFINITY-Streaming said my computer was not on the "home network" and CBR40 also disappeared from xfinity's list of my devices.]

Has anyone else solved this issue?  XFINITY APPEARS INCAPABLE OF SOLVING IT.