OTAA Join Request Not Stable

I have an RFM95 based device using the MCCI LMIC v4.0 library. The device is periodically switched on/off and the join requests are not stable. The device has to send up to 5 join requests for the connection to be established.

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One clue is visible in the output:

DevNonce already used

For the others it isn’t clear from your output, however it is probably timing related.

BTW, your requests are spaced too close together, a gateway has to adhere to the same duty-cycle a node is subject to. So some of the responses can probably not be transmitted due duty cycle limitations.

Are you node and gateway close? Make sure there is at least 5 meters and preferably a wall (or two) between them to prevent overload of the receiving circuits.