@SWHighlander Not sure, mine work, and some others here. I can only suggest to make sure you program in the APP the line in side first then the load side second in case that matters.

@Donley no the dimmer is not a three-way.

@nicholus.h how do you know it current senses?

@AustinTX all I would suggest is that you check the load side three way is indeed programmed and powered up not red LED or powered off. You should also have only one entity for the switch in the kasa...

I built a test rig to test this works, before i installed it in my house. It works just fine, as long as you replace all both three-ways and ignore teh four-ways it will work. Another place of...

Release a kasa four way smart switch product, or add functionality for two three way switch products to implement a four way solution.