Sorry for the delay. Out of pocket for several days/week. The dimmer may not display this state in the Kasa Phone App.
ISSUE with binding. There is a relatively new issue with binding. Some of the devices do not allow you to rebind the device through the Kasa Phone App (I experienced this with a light strip). Once unbound, these new devices can not be controlled at all through the Kasa Phone App. You can rebind by entering your credentials into my Kasa Integration App and then bind via the device's page. That is the only way other than re-installing the device.