Hi
I have a RAK3172 installed on a Wisblock board and 3 sensors on it. I have flashed it previously with sample code from Rak to handle sensors and it was joining LoRa network well and reporting sensors without any problems.
Now I try to use that same module for an other project (transmission of serial data through LoRa).
I have flashed in it the LoRa OTAA sample code for RAK3172 using VSCode and so far all good. Code transfers fine and I can send a AT+JOIN command to the rak3172 module.
Unhappy when I send the AT command to RUI, it first answers with OK as usual and then few seconds later I get that:
+EVT:JOIN_FAILED_RX_TIMEOUT
Only modification I have done in sample code is to be sure it’s well on EU868 band and to fill the APPEUI, DevEUI, and APPKEY.
I see well the JOIN request received on my LoRa GW but TTN doesn’t accept it as if had made some mistakes on the LoRa identifiers. I reused some identifiers I was using with previous code on that same board.
Any idea what can be wrong ?
I tried also the fill the identifiers in LSB and MSB mode but no changes at all 
Thanks
Vincèn