To get some things out of the way initially, I was able to get power to the switch and get it added by my wifi and Kasa app without any issues. It just won't actually switch the lights off and on.
I have a ceiling fan with built-in light combo. The house was originally wired to control the light only from two light switches. The fan is always on and we control the speed by pulling the fan chain. Either of the two switches would turn the fan's light on or off. The wiring setup has the source power wire coming into the ceiling fan junction box and from there two separate 14/3 wires go out to either wall switch. At the wall switch there are four total wires - one black (120V hot), one red (also 120V hot), one white neutral, and one bare copper ground.
I thought wiring up this switch would be pretty straight-forward... The HS200 has one white, two black live, and one green ground wire. I wired the white wires together, the ground wires together, one black live wire to the black feeder wire, and the other black live wire to the red feeder wire. I get power to the switch, the Kasa app has no issues seeing the switch, but it simply doesn't turn the light off/on.
I removed the second switch from the equation, wiring it together to turn the first switch (where I connected the HS200) into a single-pole double-throw.
My understanding of how these smart switches would generally be wired is that you'd use a 14/2 or 12/2 wire setup. The power would hit the switch first, and then one of your black live loads would go to the black wire from your 14/2 or 12/2 wiring, and all of this assuming that this switch is controlling a simple ceiling light - this makes the most sense with the built-in directions for installation. However, I can't seem to find any direction on wiring up one of these to a ceiling fan-light combo. I thought perhaps I needed the three-way switch version of the smart switch, but it has five wires to be hooked up to the back of the switch, so that definitely wouldn't work for my setup.
Any ideas on why this isn't working?