John,
Are you doing encryption. Is this TCP or UDP? What messages are being sent to Azure? Is your connection good? If you have a signal that is weak, TCP will cause retransmissions at a high rate. Until these questions are answered one cannot even speculate. Even UDP will take overhead that will make the 8 LoRa packet characters much bigger. I am suspicious that it is either encryption or weak signal with retransmissions, or both.
Jeff