Hello everyone,
I was having a problem where my Chirpstack server was receiving a JoinRequest from my sensor and then transmitting a JoinAccept but no uplink or downlink was being received. This problem started when I restarted my gateway today after a few days, so it was not a configuration problem. Anyway, after a few hours of troubleshooting, I decided to flush the device nonces. Apparently, that fixed the problem, but I am still not sure why the problem arose in the first place.
My sensor tries to send a message of 9 bytes at each transmission. If the transmission fails it stores the message and concatenates it to the next payload in the next transmission. It can store a total of 10 messages. Is it possible that concatenation increases payload size so much that LoRaWAN refuses to transmit that payload? And if so how does flushing the device nonces somehow fix the problem…