Uplink issues after ChirpStack registration

[HJung.5]

Hello

I'm using the NUCLEO-L073RZ board and the I-NUCLEO-LRWAN1 shield. I am trying to register with ChirpStack, but there is a problem.

After connecting power, I can check JoinRequest and JoinAccept messages from ChirpStack Application Server.

However, the uplink message sent by the End device was not received, and the End device was not activated.

Can't this board connect to ChirpStack?

[HJung.5]

Eventually I got an uplink message from ChirpStack Application Server.

But over time it doesn't come back. Then I start getting uplink messages again and the connection is lost.

I don't know when I can get uplnk messages.

On another network server, TTN, you can normally see that the end device sends an uplink message every 30 seconds.

I don't know why this happens.

I need some help.