Alexa Error with eTRV device Handler


I have developed a couple of device handlers for our Eurotronic Spirit-Zwave electeronic TRV and things are fine with the Smartthings but when I add the smartthings skill to Alexa and open the device on the Alexa app I receive the attached in the log.

I can find no information on "handlepostV3’

Does anyone have any pointers?

I am not sure if this helps but the current temperature is received by Alexa and my events seem to be received without issue.


6:38:03 PM: error Argument for propertyValue is not a String, Number, nor Map
6:38:03 PM: error getThermostatProperties: unknown thermostatMode ‘null’
6:38:03 PM: debug handlePostV3