Remote loses pairing after a few days

I have a Roamio Basic and Mini V2 in the same room same shelf (I use the Roamio basic for OTA). Each is using it's own factory TiVo remote. For awhile, like a few months, all worked well. Now, every few days when I try to use the Mini V2 there is no response from the remote. I have to pull the plug on the Mini and power back up, then all is well for a few days. Any ideas why this just started happening?

Remote loses pairing after a few days