As soon as I add the 3rd switch (a VP0SR-1LZ), I can only turn the lights on with the controller. The other 2 will only allow me to turn lights off but not back on again.
For the Leviton VP0SR-1LZ, the live cable (BK) needs to be connected. If it’s not connected, the switch won’t work.
From box 2 to 3, I only have 2 black cables, one that came from box 1 and the other that went to box 3. The one that went to box 3, I confuse it as the one that was going to the Load, when in real, it was going to box 3 and then a black cable went from box 3 to the load. This is what I was doing: