Doesn't send join request - tabs window/door sensor

Hello everyone :blush: !

The last few days, I tried to connect my Browan tabs window and door node. In the gateway “live lora frames” tab, I already can see, that the node is sending data (up events) to my chirpstack, which also contains the whole payload.
In the “device data” tab, I can’t find any frames.

Do you have an idea, why the node is not recognized by chirpstack?