First, I hope this is the right place for this question.
I have two devices based upon the same hardware and implementing the same LoraWan Semtech stack and they are located in the same room.
They are both registered in the same Chirpstack application. The differences between them are the applications and their device EUI.
Device 1: ChripStack sends a Join accept after the join request and everything is fine.
Device 2: ChripStack receives the join request message, but never sends a join accept message back.
I have finally found the reason of this behaviour:
I first registered Device #2 with a false appKey. and a correct devEUI. In this case the join request is shown in Chirpstack, but due to the bad key, the device is not accepted.
After having fixed the appKey, the device is still not accepted. I had to delete it and create it again to have it accepted by the ChirpStack.
It looks as if a device with a bad appKey is blacklisted. Is this assumption correct ?
nope, based on incorrect appkey chirpstack generates incorrect session keys etc. per each device, in this case you need to re-create the device. be careful while you add the endnode device