MQTT action Publish can't send message include special character

  • Platform information:
    • Hardware: Raspberry pi 3+
    • openHAB version: 2.5.
      Hi everyone, i using MQTT action to publish item state to mqtt broker. But when my item state include special character or vietnamese character like “Mây cụm”, my mesage received include “?” character like “M?y c?m”
      I don’t know if openhab3 can troubleshoot this issue.
      Can someone give me a good idea?