Hi @Carl I owe you something of an apology. I decided to double check which side of the circuit the line/load wires were, and sure enough, I had the smart switches on the wrong ends. Swapping them...

@Carl Thank you for the reply. I'm quite certain the switches were installed on the Line side, as the other side does not have all five wires (two travelers, line, ground , and neutral) to install...

Hello. I recent installed five S515 3 Way Smart Switches (along with many other S505 single pole switches throughout my house). Two of them work fine, but the other three have pretty much the same...