Class C downlink DR

Hello,

I have a RAK Gateway and a device configured in class c. The loraserver has rx2_dr=5 and is configured for the EU region.

I manage to join successfully and send a packet upstream. The loraserver at this point automatically sends a packet downstream at DR5. What is this packet please ?

Then i try to send a class c packet from the loraserver. The packet is received by the device, however it is at a DR0. Why it does not take the configuration of the .toml file please ?