Possible workaround from EA sources:
WORKAROUND:
Note the letters (or challenges) you are missing for that War Story - you'll need that information later.
Delete your local save files (not the game). This will reset the War Story progress and your game settings - you won't need to complete all of the challenges again, only the missing ones!
Once you deleted your data, play the War Story again. Again, you would only need to collect the letters and complete the challenges that previously were shown as not completed.
When you complete the War Story and gather the missing Letters or complete the Challenges, you'll have the unlock! Enjoy!
Hopefully that will help.
tried restarting the campaign and doing it all over again did not work, where are the save games located for single player?
