Mysterious problem with x1 box and remote

Last Saturday (10/5) - my X1 main cable box with DVR stopped responding to the remote.  After 2-3 hours communicating with Xfinity Assistant and then human chat - it was decided that I needed a new box.  A technician came on Monday (10/7) and installed a new box and gave me a new remote.  The remote paired with the box with no problem and everything seemed to be working fine.  The next day, however, when I turned the TV on - it would not respond to the remote.  After about five minutes - it responded again until I turned it off.  Now on 10/11 - sometimes the box will respond after a few minutes and sometimes I have to unplug the box for a reset since I can't reset through the TV since it is not responding to the remote.  After another chat with a human and two calls from "Advanced" technical support - which basically refreshed my signal and did not solve the problem - another technician is coming Monday to "resolve the problem for sure".  No one seems to know exactly what the problem is though.  I'm posting this to see if this has happened to anyone else.  Obviously something is not communicating with something else - but there is no apparent reason since it will work fine with every restart.  I am very frustrated and wish that the advanced technical support actually was advanced. Thanks for any help anyone can offer