Thermostat Fan Mode "Updating"

I’m developing a Z-Wave Thermostat and communicating with the standard Android SmartThings App.

When I tap the “Fan Auto” tile at the bottom, it changes to “Updating” and stays that way. I can get it back to “Fan Auto” by going back to the previous menu and selecting the device again.

I’ve tracked the Z-Wave communications with the Zniffer and I seem to be responding to the correctly but the Android app doesn’t seem to agree.

Is there something wrong with the way I’m formatting the Z-Wave response or is it SmartThings?