Thanks for reaching out to us in the land of the forums. We do apologize that the skinned remote that you are using is not working. We are happy to help.
Normally when this happens, the most likely cause is that the IR Blaster cable is not actually in the correct position of the IR window on your new cable box. Down below, we have provide two great articles that will explain a little more. The first one is very basic and talks about positioning and the second one offers some more advanced steps that can be tried.
Hope this helps,
The Slingbox Moderation Team