XR16 Remote Voice Control not working

I have an XR16 voice remote. It no longer takes voice commands. I have replaced batteries, tried reprogramming, and did a factory reset. After doing the factory reset, I had difficulty getting the remote to control my TV but eventually got that to pair. However, it still will not pair for the voice command. The flex box and remote are both originals and are older. Do I just need a new remote or what do I need to do? And how much is it going to cost me? I didn't start having problems with it until they upgraded my modem. That is when the problems began, but I always just changed the batteries and that seemed to work. I attempted to use the XFinity Assistant and it was no help whatsoever. It kept repeating the same things which was what I had already done.