Downlink no longer works

[IoTThinks]

The device can join LoRaWAN network and I can send a downlink packet.

The device "hears" something but can not print it.

Last year, I tested downlink ok. I suspect the new code broke the downlink. https://github.com/ElectronicCats/Beelan-LoRaWAN/blob/master/src/arduino-rfm/lorawan-arduino-rfm.cpp#L506