LoRaWAN unconfirmed downlink and re-JOIN procedure

Recently I started working on LoRa-enabled devices and noticed that some of them do not handle case when they are unprovisioned from Network Server. This happens a lot during development (especially if NS is under development too).

Here is what happening:

• LoRa device provisioned on Network/App Server.
• LoRa device sends JOIN and succeed.
• I deleted the device entity on the Network Server and add it again. This cause deletion of the session keys that are generated during OTAA and cleanup of the devEUI
• LoRa device keep sending the data, and it is rejected on the server.
• LoRa device does nothing to handle it and keeps sending data.

Some devices send JOIN again when power-cycled. But not all devices can be power-cycled at all! Some meters I've seen rejected to work after their hard-wired battery that when re-attached!

Is there any "common" approach of how device should detect/handle such kind of "disconnection" from NS?