I'm on 0.0.9c and whenever I get a customer that has a shield in their order they doesn't leave after I finish their order and they have both items
I believe you paid $5 for testing that version?
Well, I have seen a Youtuber (IGP) and he had the same problem, to fix that:
1 - Give the armor to the customer
2 - Save the game through main menu (not auto save)
3 - Quit to main menu or quit the game
4 - Rejoin the game
5 - Problem solved :D
I also found you can do the same thing with going to sandbox mode and switching back to fix it.