I don't see any problems. I have an assumption that it's because of the custom map. Try adding a custom spawnpoint with the afe_addcustom command a little higher from the ground to be sure that the crates will not end up underground. Don't forget to change in the config - "Use a custom place to land a cargo plane": true. Check if there are errors in the console when the plane drops crates. About the plugin from Steenamaroo, I can't tell you anything, unfortunately, I don't know how these NPCs work, try contacting the developer. After the tests, let me know the results, please