Can't Cycle Thermostat Mode: GoControl GC-TBZ48

I have a Go Control GC-TBZ48 thermostat hooked into a SmartThings hub. I can cycle the Fan setting between Auto and On by pressing the Fan button in the control panel for the device. But I can’t cycle the Mode setting. When I try, by pressing the Mode button in the control panel, it hangs on Updating… for a long time, and then reverts back to Auto.

I looked at the notification messages, and while the Fan cycling shows messages about the requests being processed, there’s nothing regarding the Mode cycling.

Is it not possible to cycle the Mode remotely? I thought I’d done that in the past, but maybe I’m hallucinating…

I too have the same issue with this Thermostat. On the smartthings app for the device, I can press the System button (Auto) and I just get a message “Updating…” Nothing changes.

Smartthings show the thermostat supports the following modes.
supportedThermostatModes: [off, heat, cool, auto, emergency heat]

Ran out of propane in family cabin 200 miles away, got propane filled and now need to reset the Thermostat (Off / On) remotely to get furnace to retry.

I have the same problem. The app is supposed to cycle from Off - Heat - Cool - Auto - Off. Every cycle works except from Auto to Off, which hangs at “Updating.”