Just installed a TP-Link HS210 in a circuit that had two three-way switches and a four-way switch. I made sure to install the HS210 to replace the first three-way which was fed with power from the circuit breaker. Electrically everything works fine, I can turn the lights on and off from any switch and can turn them on from a given switch and off from another switch fine with no problem. The issue is that from the Kasa app and from the Alexa app I cannot tell the status of the lights. Both apps show the status of the light as off even though it is on. When I click the icon to turn on it turns green for a second and the light physically turns on but shortly afterwards the icon goes grey even though the light is on. In Alexa when I turn it on it will go on and the icon goes green but then the icon in a few seconds shows off - it will over 20 seconds or so switch a few times between on and off and then will stay at off even though the lights are on.
HS210 status is wrong in app