Hello Urs,
Thanks for your pointers.
I can overcome the problem if I uncheck 'Create Garmin GPS flight plans' in the Display Unit /Settings/Miscellaneous.
You are right, when EFB changes the FSX flight plan, FSInn mirrors the change.
Okay, with the option 'unchecked' no changes are made to the FSInn flight plan.
If you are using the Garmin GPS with the option 'checked' then any change you enter in your flight plan, you must remember to reload the original flight plan in FSInn otherwise it will show ALL waypoints as 'DCT' removing any airway idents.
I often wondered, when on VATSIM as a controller, why some of the flight plans included all the intersection waypoints. They could be using EFB and are not aware of the stealth changes. It is possible the same could be happening when using Squawk Box.
Hope this make sense!
Regards
Don