ZigBee callback not working

[CDeve.2]

Hi,

I am using a STM32WB55 board and its USB Dongle.

I set up a ZigBee network with Messaging Cluster between them.

The WB55 is the router + server, and the Dongle is the coordinator + client.

I can send a Message from WB to Dongle.

When I try to send data from Dongle to WB, the callback on WB is never called, even when I send the message to everyone (broadcast).

What can make a Callback never activated?

Best regards,

CD

[CDeve.2]

Did I send data to the wrong address?

Why the broadcast hasn't made the trick?

 dst.mode = ZB_APSDE_ADDRMODE_SHORT;
 dst.endpoint = SW1_ENDPOINT;
 dst.nwkAddr = 0xffff;

I've seen this: "Before joining a Zigbee network, a device with an IEEE 802.15.4 compliant radio has a 64-bit address that is globally unique." from the datasheet.

How can I find this address?