MQTT HVAC - mode_command_topic

Hello,

I’m trying to setup an MQTT HVAC entity over MQTT discovery.
Below is the configuration message that is sent to the homeassistant/climate/maxair/livingroom/config topic:

{
	"modes": [
		"auto",
		"off",
		"heat",
		"dry",
		"fan_only"
	],
	"temp_unit":"C",
	"force_update":true,
	"availability_topic":"MaxAir/availability",
	"away_mode_command_topic":"MaxAir/away/command",
	"away_mode_state_topic":"MaxAir/away/state",
	"unique_id":"maxair_livingroom",
	"name":"MaxAir Living Room",
	"mode_state_topic":"MaxAir/SC/mode",
	"mode_command_topic":"MaxAir/SC/command",
	"action_topic":"MaxAir/livingroom/state",
	"action_template":"{{ value_json.hvac_action }}",
	"aux_command_topic":"MaxAir/livingroom/aux_command",
	"aux_state_topic":"MaxAir/livingroom/state",
	"aux_state_template":"{{ value_json.aux_heat }}",
	"current_temperature_topic":"MaxAir/livingroom/state",
	"current_temperature_template":"{{ value_json.current_temperature }}",
	"temperature_state_topic":"MaxAir/livingroom/state",
	"temperature_state_template":"{{ value_json.temperature }}",
	"temperature_command_topic":"MaxAir/livingroom/target_temp",
	"json_attributes_topic":"MaxAir/livingroom/MySensor",
	"device":{
		"identifiers":[
			"maxair_livingroom"
		],
		"name":"MaxAir Living Room",
		"model":"MySensor", 
		"manufacturer":"PiHome"
	}
}

Everything works well apart from the mode command. When I try to change the mode from the lovelace thermostat card no message gets published on the MaxAir/SC/command topic. Is there something else needed for the command message to be sent?