I need help troubleshooting my HS210 switches. I bought the HS210 Kit and am using the two switches on two separate 3-way sets. I'll call them set A and set B.
My HS210 is on side 1 and a normal 3-way switch is on side 2. When I wired the HS210 on side one, I found which wire was line in by checking it against ground. Then the travelers aren't supposed to make a difference where they go (right?). Following basic 3-way switch diagnostics, I linked the side 1 wires (line in and the two travelers) together and tested the wires on side 2. Two wires had house voltage and the 3rd wire did not, which means it's the load. I rewired the side 2 switch accordingly. With both sides wired up, I went to the Kasa App to set it up. During set up I tell it I'm only updating one switch and everything goes great.
Now the problem: With side 2 in the "up" position, the app button cycles the switch on side 1, but the light doesn't come on. I hear the physical switch trying to turn the light on or off with every press, but the light doesn't turn on. Pressing the virtual app button goes like this: off, off, off, off. With side 2 in the "down" position, the kasa app button turns the light on, then off, then pressing the button again, the switch doesn't turn the light on. In other words, pressing the app button goes like this: on, off, off, off, on, off, off, off.... This setup means that I CANNOT reliably know the status of the light in Set A. I can hear the physical switch turning on and off on the first cycle, (first and second virtual button press), but no sound during the third and fourth virtual button press.
The physical switch works fine and cycles normally on, off, on, off, but only when side 2 is in the correct position, otherwise it's off, off, off, off.
Things I've tried: rearranging the travelers and load on side 2 switch but that only inverted the side 2 switch positions function or killed the function altogether. I've reset switch a few times and the same functionality remains.
Followed the same setup as SET A and also only works when it's side 2 is in the proper position. However, a key difference is that the app's virtual button power cycles normally, on, off, on, off the same as the physical button.
I can be ok with the SET B functionality, but the SET A fault in the app (and the same holds true via Google Home, which makes sense since it communicates through TP Link's protocols the same as the KASA app) makes this switch unreliable for scheduling and scenes (unless powering off).
Is there anything happening on the wiring side that I'm missing? I do have a mess of wires in my 3 gang box since both HS210 switches are side-by-side with a normal single pole switch. There are a number of neutral wires, which I'm assuming share a common neutral to the main panel. If I'm wrong on that, how do I troubleshoot which neutrals are allowed to pair with the HS210 switches? Is this problem with firmware and the KASA app? Do I have a defective switch(es)?