This also happened to me yesterday when I got home from work. Had live TV and yellow light would go on when pressing the remote but it would not respond or do anything. Had to pull the plug. Only on my Roamio Plus though. Others seem unaffected. It has happened twice now since the 20.4.5 update.This happened to me for the very first time, also yesterday. I can't pinpoint when it stopped taking remote input because I was out all day, but when I returned home at 7:30pm Wednesday night, I had a live signal working fine through my Roamio, but it wouldn't respond to any remote signal (although the light would flash on the front of the box, so it was aware the remote was being pressed). My first thought was that it was related to the remote's ID code (I have 3 TiVos and 3 remotes, all set to different codes). But I thought the easiest thing to try was a reboot, so I yanked the plug, plugged it back in, and everything was fine again after the reboot.
Now that I've read this thread, I'll try disconnecting the cable in and the Ethernet before a reboot if it happens again.
It's pretty clear that this isn't happening at random times. It's happening on VERY SPECIFIC DAYS. I don't know what that means, but it clearly means something.