All, maybe this will help the developers : one of my Stelpro ZWave Thermostats is recognized by Smarthings as “Generic Z-Wave Thermostat” I am not sure why it was recognized this way but it is the only one not affected by the problem.
I still can change the temperature or switch modes. Other 9 thermostats are recognized as “Stelpro” and affected by the problem. If Smarthings would start recognizing all thermostats as “generic” - it could solve the problem.
Meanwhile - there is a workaround that appears to work (credit to this post Stelpro STZW402WB+ Unable to adjust temperature - #5 by ag2000)
- Open the Google Home app and ensure the Google account listed is the one you used to set up your Google Home.
- Tap the + in the top left-hand corner.
- Tap “set up device”, then Works with Google.
- Search for SmartThings and tap it.
- You’ll be asked to sign into SmartThings: Enter your Samsung or SmartThings account email address.
- Authorize the link, allowing access to locations.
Note that you do not need neither Google nor Amazon hardware, your Apple or Android apps are sufficient. I was able to apply the workaround while being remote (no need to be on the local network with your devices while setting it up).