Hi MartinM
I have the same problem like you . Did you solve it?
I have my own GW so I can check all traffics. Every 6 hours send my QALCOSONIC E3 a “Join-request” message but TTN ignore it.
NEWS: I solved my problem with just dismounting of LORA module from the main board connectors and installing it back. Lora modul sent a new Join-request message and TTN recognized my device.