Voyager III units with Symbio 700 controls ship from the factory with the Space Controller Option set to a Zone Sensor. When configured this way, the unit will ignore the thermostat inputs. If convention t-stat operation is desired, change the Space Controller Option in CONFIGURATION from Single/Dual Setpoint Zone Sensor to Conventional TStat using the onboard UI, Symbio App, or Tracer TU. See link below for related article and configuration.
How to Change from a Zone Sensor to a Conventional Thermostat