NeoFly help/guide?

Greetings folks.

I stumbled across NeoFly add on which looks interesting. However, I cannot get it to add cargo. Near as I can tell my payload window in MSFS keeps resetting to an auto half fuel load which may be preventing me from loading cargo.

The Failure Mode: I set up the mission in NeoFly, set the correct depart and arrival locations, (using ramp and a cessna 152) I am choosing the lowest weight cargo mission listed, usually around 350-400. All parameters appear correct and green dots except cargo. Attempt to adjust load in MSFS and like I said, fuel load keeps resetting itself to 50 percent (maybe 54%). Engine start and still no cargo load. I have looked at a few Utube guides, no help. Any help appreciated