RAK811 not send ack when received any downlink and Network Server only try to resend one time

Hi all, i’m using rak831 gateway and rak811 node base on AS923 frequency plan and class C support.
My problems are:

  • When sent with confirmed downlink, rak811 received successfully data but no reply ack (checked by using lorawan frame on webserver). And the server only try to resent down link one time.
  • When using class C, maximum datalenght sent is only 4 byte, the longer will not received and the rak811 send “unknown network error” on serial port.!

it fully depends on microcode inside your RAK811 device.

i used the default firmware from manufacture! Let’s i try to the newer!
But i still not understand why server is only try to resend one time? where to config this value in chirpstack server?