Downlink messages enqueued, but not sent

Dear Community members,

I have a following configuration:
- gateway: Nucleo F746ZG board with LoRaWAN shield
- end device: Nucleo WL55JC1.
Sofar, I have successfully deployed my network on The things network server, but unfortunately was not able to deploy it locally. For this project, I need a local network server and have decided to go with Chirpstack Network server.
After launching the docker image from this link: GitHub - chirpstack/chirpstack-docker: Setup ChirpStack using Docker Compose,
I have tried to register my gateway and end device. With the end device, I did not have any problems, but gateway has been acting a bit strange. On the dashboard, it says that the device has never been seen, but it is still receiving uplink messages from my end device.
However, when I try to send some downlinks, they just stack on the enqueue list, but never actually get send away.
To clarify the situation more properly, I am sending some pictures in attachment.

Looking forward to Your answer.

Best regards,

You’re looking at the raw LoRaWAN frames. Look under the Events tab to see if the device has successfully joined and payloads are being received and decrypted.

Here is the event tab and as You can see, I am receiving uplinks, but unfortunately cannot send any downlinks.

Are you using Class A or Class C?
If Class A, the downlink will be sent to node via the same frequency with the uplink.
If Class C, the downlink may send to RX2 window. You can check the setting of RX2.

If you use high latency line (3G,4G…) for gateways, you may want to increase the delay to send downlink.

I am using Class C device.

In the attachment, I am sending the picture of gateway dashboard.
Where Can I adjust those delays? I cannot seem to find it in the network server

In my Docker log, I am getting these messages about downlinks, but still cannot see any of this in my network server. Also, none of the messages get actually sent to the end device

You can check the Region tab.
You may need to check the RX2 frequency in node. Some nodes hardcode the RX2 frequency.
RX2 frequency in server, gateway and node should match.

As already mentioned before, you are using a single-channel gateway. Most likely your issue(s) are related to the single-channel or incomplete packet-forwarder implementation that is used on this “gateway”.