I have 2 3-way mechanical switches and a 4-way mechanical switch between them controlling a light fixture. I replaced the load-side 3-way switch with a Caseta Pro dimmer (PD-10NXD). The Caseta dimmer is wired with the blue wire connected to one of the traveler wires (red) and the black wire connected to the other traveler wire (black). The red wire is connected to the load. The white wire is connected to neutral, but whether or not that's connected doesn't seem to affect the circuit's function.I rewired the hot-side 3-way dimmer per the advanced instructions, with the hot wire and one of the travelers tied together and connected them to the different colored screw on the 3-way switch (I didn't use the yellow jumper wire because it seemed to do nothing besides add unnecessary wire to the box), and the red wire (the other traveler wire) on the brass screw, with the second brass screw not connected to anything. That switch and the Caseta dimmer work fine. My trouble is that the 4-way switch behaves "strangely." Sometimes it works to turn off the fixture, but other times it does nothing. I'm not entirely sure how to wire the 4-way switch for the circuit, but the best way appears to be to leave it how it was wired before. Perhaps there's no way to wire the 4-way switch to work in this circuit? I guess I could tie the two black and two red traveler wires to each other (removing the switch) and replace the 4-way switch with a Pico, but I was curious if there's a way to have a 4-way switch in this circuit without doing that.