Thanks, That would explain the difference.
I tried doing a "mac save", but as expected this does not save state information. Also a reset to the reset pin clears the join and frame state as well
The rejoining gives an additional MQTT event, but that is not a problem for me.
I guess my question is whether rejoining every time for low duty cycle node is OK?
Thanks to Charles for his code snippet. It helped with a different problem I have to get out of an unintentional autobaud state when changing serial pins in Micropython
Using the packaged RN2483 and the packaged Micro:Bit with Micropython is interesting, and to some extent meets my original goal to find a more sharable "on-ramp" for TTN and Open IOT, but sometimes, I get the urge to get back to bare metal SX1276, M0 and C++.