I replaced a Kasa on/off with an HS220 dimmer and set up the wifi.

Light will not turn on or off.

Wiring is correct. I can connect the dimmer to wifi and control it, and I see the dimming LEDs on the switch turn on and off, but the light does not turn on or off.

Light has 25 GU10 Base LED 6W 120V.  (by my math this would be 150 W total)

The dimmer is rated at 150W LED.  25 6W GU10s would be 150 W.

I see that the on/off model is rated for more LED than the dimmer. I forget the number on the back of the switch but it was more than 150W

Serial number Y239151001352. US 3.6.  VN1

Reverted to the Kasa on/off and it works fine.