Group the channels.
Were both sets of DMS channels automatically created (without user inputs)? If the second set was manually set up, you would have been asked whether you wanted to group. If you did not choose to group when asked, or you were not asked, then you will have to try one of the following methods:
1. Select the two channels that you want grouped (for example, channel 5.1 on device 1, and channel 5.1 on device 2), and right-click > Group Channels. This is very tedious as you have to do it channel-by-channel.
2. Click "Auto Group" button. This will go through all your channels and try to group channels that look similar. The result is not always accurate. It will group your Cable CARD channels with other types of channels, not just DMS channels.
I don't have two identical devices, so it is not possible for me to verify the result. I just tried clicking "Auto Group", it did group some of my channels but did not group my DMS channels. I guess I need to look into that part of my code and make sure it works for DMS channels.
Also I think the following functionality is missing: "Auto group selected channels" - i.e. apply "auto group" logic to selected channels only, not to all channels.