RAK7258 How to change downlink DataRate

I use:

  • Gateway - RAK7258 (v1.3.6) in built in Network Server mode.
  • End device - RAK 7431 terminal in P2P mode
  • MQTT client to communicate with end device (upload/download data)

I need to send/receive payload more then 50 bytes.

When both Gateway and End Device worked with active ADR mode, I can not send and receive data.

When I set RAK 7431 module:

  • ADR parameter = Off
  • DataRate = SF8BW125
    data from End Device correct send to MQTT.

But when I want to send data to End Device (using MQTT or Built in Application-Device-Downlink interface), Network Server set DataRate always SF12BW125. So I can send effective payload only 36 bytes!

How ADR algorythm works? How to Setup Network Server to communicate with End Device on heigher DataRate to send more data in packet?

Thank for answer