@MikeLeeds 

When you set different temperature settings for the Kasa thermostat at various time intervals through Smart Control, the device calculates the valve opening and closing speed based on factors such as environmental temperature and machine operation conditions. To maintain a constant temperature and avoid frequent valve adjustments due to temperature changes, the valve won't fully close after reaching the set temperature. Consequently, the flowing water may cause a slight temperature increase, which is a normal occurrence.

As for the situation you mentioned here, can you help to check some information to verify if this is an unusual problem or not?

"I tested each one and found that after turning the valve to show a different temperature, there was no motor response from the control at all... all the way from a high temp down to 5 degrees. "

1. Did you adjust the temperature directly? Or did you change the temperature setting in Smart Control?
2. Did you make the change through the Kasa App or Alexa (App or voice control?)?
3. How long did you wait to observe the temperature after changing it?

4. Enable the Sleep mode (Device's Settings page), check if the valve can be fully closed.