Hi Alexis,
Are you using Class A/Class C mode while transmitting data between the MDot and conduit. Because in Class A if you send a packet from the MDot to the conduit and the conduit needs to have already queued a packet in response even before the MDot packet made it to the conduit.
So what I am trying to say is if the response to the mdot packet is generated after it was received by the conduit, you will receive an empty packet if nothing was queued previously on the lora downlink queue for that mdot. So when you transmit the next packet from the mdot, the conduit will send a packet that you last queued. Hope that makes sense?
Thanks,
Ajay