Remote keeps forgetting IR settings

I bought a new remote for my Roamio yesterday (a TiVo RF/IR). I paired it with the Roamio, and then went through the process of configuring it to turn my tv on/off and adjust the volume of my receiver. Everything worked great for one night.

This morning, neither the TV on/off nor the receiver volume up/down worked with the remote. The TiVo functions worked fine.

So I went back into the remote setup and configured the TV on/off and receiver volume again. And they worked again, for less than an hour; I noticed a few minutes ago that they stopped working again. So I configured them again.

Am I missing something obvious here? Why would the remote keep forgetting the IR settings (I assume it's the remote that is having issues?)

Thanks,
Jeff