Yodasector wrote

So I have installed my HS210 3 Way per the instructions but it is behaving incorrectly.  If I hit the switch connected to the lamp, it will turn on and off as expected, but when I use the other switch both switches go dark (like there is no power) and the lamp will flash on and off.  For wiring I have followed the instructions on line with regard to the travellers and the line load on the previous switches and connected them accordingly..  The power runs into the switch that causes the lamp to flash when as line and the lamp is connected to the switch on line load..  The other 2 Red / White are the travellers (as wired)..  Any thoughts on the issue..?

@Yodasector 

If you searched and looked up info on the Kasa HS210 3 way kit.. you'd learn that each switch is fully functional and can also be used separately with a non smart 3 way switch.   In additional to being more economical.. iit also simplifies the setup.   If anything.. just try wiring it up with only the one HS210 and a regular non smart switch..  to ensure the correct wiring, are identified and labelled..