The CM15A does not do well with distance as far as RF goes. You could possibly try an RR501 in the areas where it is sporadic to pick up the slack. I had done this in a couple places in my house before I did an antenna mod on my CM15A which now covers my whole house for receiving my remote signals and getting them to the HA computer.
The other issue may be a distance issue for the PLC signal. How far is the CM15A from the breaker panel? Also, how far is the socket rocket and WS467 from the breaker panel? Add the two distances together and that is approximately how far the PLC signal will have to travel. If the CM15A is a ways from the panel, you may want to move it closer to it. You could have your CM15A at one end of your house right below the room where your rocket and switch are, but if the panel is on the opposite end of the house, the signal will need to travel all the way to the panel from the CM15A and then all the way back to the upstairs room, and that could be quite a distance.
Dan B.