TP-Link Kasa HS210 kit and 4-way switch circuits

tl;dr: If you are having problems with the Kasa three-way switch in a four-way circuit where the Kasa app and Alexa don’t see the right state of the circuit (on/off), make sure you replace both three-way switches in the circuit with HS210 switches. That will fix the problem. For a change, I’m writing about some…