MQTT set power (OFF) and set mode (ON) seem not to work

[p-ranit]

Hi, I uploaded the firmware to wemos D1 mini and successfully connected to my HVAC. From the web page everything works great (on/off, setting mode, temperature, etc.). Using mqtt (mosquitto_pub -d -u xxx -P yyyy -t mtsb2mqttsala/Split_Sala/power/set -m OFF) I can't turn off the HVAC system. Likewise (mtsb2mqttsala/Split_Sala/mode/set -m ON) I can't turn on the HVAC. Conversely, if I send the command mtsb2mqttsala/Split_Sala/mode/set -m HEAT the HVAC is powered and starts heating. Where am I wrong? I have another doubt: the guide states that I can use topic/power/set OFF but not topic/power/set ON. Did I get it right?