This is a very difficult problem. I have two cable boxes at my home. One is used for home viewing, it's an Arris DCX3600-M with DVR function, and when I travel, I use the other one, a Samsung SMT-H3362. Both are provided by Time Warner Cable (now Spectrum). My problem has been that when I issue commands from the laptop, the channels change on BOTH the Arris and the Samsung. At first I suspected that the problem was due to both the Arris and the Samsung being programmed to respond to the same remote commands because they use fairly identical remote control units. I worked on isolating the Arris from the IR beam of the SlingBox IR blaster. Layers of foil, sealed edges, nothing worked. As a crazy idea, I actually disconnected the IR Blaster from the SlingBox. As expected, the Samsung box stopped following my commands. BUT strangely, the Arris box and its connected TV continue to respond to the commands I give from the on-screen remote, EVEN WITH NO IR BLASTER CONNECTED. The Arris box must be receiving its commands through an EtherNET network or HDMI cable connection, but this capability must be undocumented.
Anyway, The outcome I want is that only the Samsung box follows the commands, and the Arris box must ignore the commands. Can ANYONE come up with a workable solution?