Downlinks not acknowledged or sending

I’ve run into a problem with downlinks on my loraserver. While I am receiving uplinks as expected on both the gateway and the web application, and seeing them coming in on the MQTT topic from the gateway (“gateway/{{gatewayEUI}}/rx”), I am not able to send downlinks either by the API or by sending to the correct MQTT topic (“application/{{appId}}/device/{{devEUI}}/tx”).

I am running a Class C device that I have used to make several uplinks throughout the testing (so a lack of that first uplink is not an issue). I have also switched it periodically to Class A, wondering if that was the issue, but no downlinks were sent immediately after its uplinks then either.

When I use mosquitto_pub to send a message to the above topic, I can see that it has been received on the “lora/{appId}}/device/{{devEUI}}/tx” topic, but it is never acknowledged by the gateway on the “gateway/{{gatewayMAC}}/ack” topic or by the application on its acknowledgement topic.

When I use the API to POST messages to the queue, they simply sit in the queue (which I can see with a GET request) and are likewise unacknowledged and unsent.

The messages I send to the MQTT tx topic do not ever appear in the queue, according to the API GET call.

I am using a Laird gateway, set up as an MQTT forwarder with the instructions provided here ( with the latest firmware and as mentioned, I am getting uplinks successfully, just zero downlinks. The MQTT username and password has been set on the Laird gateway’s web interface, and the config files of the loraserver, lora app server, and lora gateway bridge.

Any help as to what I am doing wrong or haven’t properly set up would be greatly appreciated.

Apologies, it was an issue involving our Docker containers being set up without correct configuration, and the loraserver being unable to dial the lora-app-server.