I was trying to setup A,B,C buttons which were not working earlier (or may be I didn't know how to use it, but I know now)
Now they are working fine.

Before these steps, I could use the PIP on my comcast remote. When I pressed [PIP] on/off, the smaller window would pop up on TV and I was able to use rest of the PIP buttons to control the smaller window.

But now I am unable to do that.
Nothing happens now, when I click the on-off button.