Voice control not working

I'm trying to help my elderly neighbor and customer service is absolutely no help. Her remote won't respond to voice commands. All other functions work, on/off volume. If we push the mic button it tells us "somethings not right, try again later". We've paired, unpaired, paired again,  made two calls to Customer service totalling 1.5 hours with no resolution. Their response is go get new remotes. I took the remote from her bedroom and tested it there and it responded to voice commands. I brought that remote out to the living room and paired it with the tv out there (replacing the remote that wouldn't respond). It did not respond. Took it back in the bedroom and paired it to that tv and it worked again. This leads me to believe that this isn't a remote issue. My neighbor just wants to speak into her remote.  She can't seem to get the hang of using the guide or just entering the channel number. This is important to her and I can't seem to get any resolution.  Please help!