Downlink data sending error

I have seriously encountered a problem with sending downlinks. I share a screenshot below. I want to send simple 0 and 1 for on and off of a custom Arduino-based Lora node. but unable to do that. Even I send the downlink confirmed data from port 2 but Lorawan frame shows fport 0 and unconfirmed downlink data.

Please help me to send the downlink successfully…

Please note that it could be that your downlink payload is still in the queue. What I see from your screenshot is that the NS is trying to configure additional channels using mac-commands. If your payload + mac-commands do not fit within one downlink, then mac-commands will be sent first to the device.

Thnks brocaar.It helpes me in my work.