Hello,I have a 3-way installation with “old” Leviton on/off switch. I want to replace those two switches by an RRD-6CL dimmer and its companion the RD-RD dimmer. I installed the RRD-6CL on the load side and the RD-RD. I am able to control the lights with the RRD-6CL (the LED on the dimmer turn on) and I cannot control the lights with the companion switch. Nothing happens when I push the button on the RD-RD. I tried swapping the two dimmers but when I do that the lights do not turn on at all.Can someone please help me understand why I would not be able to turn on and off the lights with the companion dimmer?Thank you! I really appreciate the help!