There is a bug in Erp.Internal.OM.ImportEDI.dll that handles importing .app files for the demand Import EDI Process.
CheckBox fields in DemandHead are not set to what is in the .app file. All CheckBox fields are set to whatever the value is of CheckBox01 in the app file. The program iterates through the fields when setting but uses the value of CheckBox01 on each iteration.
Hopefully this saves your sanity if you found this. It’s not just you 
no matter what support tells you.