2GIG (GoControl) Thermostat STZ-1 -- Cannot Set Temperature

[jaydrosy]

Hi all.  I'm not sure if this is the right forum, but I figured I'll try here.  I'm working to get rid of all my Insteon stuff in my house, and am upgrading everything to Z-Wave.  I'm running EISY with ZMatter, by the way, and generally things run just fine with all my existing devices (mostly light switches and door locks).

I picked up three of what I thought were GoControl thermostats but are branded as 2GIG, model STZ-1.  Two are now installed.

I've had no trouble adding the thermostats to my network.  The thermostats also are mostly able to be controlled by my EISY using the Admin Console, and all local changes at the thermostats are immediately reflected in Admin Console.  So, I can turn the thermostat off using Admin Console (and UD Mobile for that matter), change to heat or cool, change the fan mode from auto to on or back, no problem; and any local changes made are reflected immediately.

The single exception is temperature control.  If I adjust the temperature on the thermostats, those changes are immediately picked up by my EISY/Zmatter and are reflected in Admin Console.  If, however, I try to adjust the temperature from the Admin Console, I get an error saying "Cannot Communicate with [DEVICE].  Please check connections."  (see image below).  This happens with both Thermostats. 

Any ideas what I'm doing wrong or might fix this?  I've rebooted EISY just in case.  I've done "Update with Interview" on each device, just in case.  I'm at a loss.  Any help would be much appreciated.

Thanks!