I think your question needs more context. If you enqueue a downlink, then it is expected that it will only be sent once, because after sending it it will be removed from the queue. If the queue is empty, there might be an initial downlink for mac-commands and once completed no further downlinks are required.
If you have anything to send to the device, then you enqueue a payload, which will be sent as downlink at the next downlink opportunity. If not, then it is perfectly fine that you will only see an uplink in case of UnconfirmedDataUp payloads.
Yes, it’s true that we only see the UnconfirmedDataUp payloads status. How do you make the uplink and downlink processes run normally.
Is there any configuration that we need to adjust?
If there is nothing pending in the queue, there is no acknowledgement required and there are no mac-commands to send to the device, it is normal that there are no downlinks.