I've recently replaced 3 3-way light switches and a 4-way light switch with the PD-6WCL dimmer and pico remote(s), however I've noticed that 3 of the 4 dimmer switches have a very faint buzzing or humming noise when they are not turned on. They do not buzz when the light is on all the way, nor do the lights themselves audibly buzz. To install, I followed the video instructions suggested in the documentation that came with the switches (https://www.youtube.com/watch?v=hvjub64St3Q). I first identified which switch of the 2 existing switches had the "hot" or line wire. I connected that wire to one of the two black wires on the dimmer switch. I then connected the other 2 traveler wires to the other black wire on the dimmer switch. In the other box, I connected all 3 wires together with a single nut. Everything works as expected with the light, but the faint buzzing is concerning and it doesn't seem to matter what bulbs I have in the light fixture or if I even have any installed at all. That seems to tell me that there is still some current flowing through the switch, and that seems wrong to me. Any thoughts?