Is there a bug tracker for smart things? this bug has been around a long time.
if you create a device handler and set default values, the android smart things app doesn’t see them, when you try to save device preferences the app asks you to fill in all the values, even though the device handler has already entered all the values for you
the best example of this is rajivs Fabaro dimmer code found here Fibaro 2 Dimmer (212 not 211)
which will not work when used on android, unless you first set the values using either an iPhone or The IDE, the IDE doesn’t work well either because it doesn’t restrict the values like the smart app does, so you can enter any number or text you want into the input box.
I had the same issue when developing a sony bravia device handler when i wanted to put default values in, it broke the device handler on my phone. this was a problem for me on a Nexus 6p, samsung galaxy s5 and a google pixel XL