DIS Entity created at the wrong coordinates

[gengle2020]

I am using custom software to send an entity state packet to Prepar3d v5.3. I see that the entity is created, but it always appears at 0 degrees latitude and 0 degrees longitude. Using Wireshark I have verified what I am putting on the wire is correct, and for troubleshooting, instead of calculating my own X,Y, and Z coordinates I used Wireshark to read what Prepar3d was sending out for its entity and used that position to feed back in to Prepar3d.
Looking at the entity state PDU from prepar3d and comparing it to the entity state PDU that I am generating, only the entity ID, timestamp, and entity marking are different at this point.
Has anyone else encountered this before?