So tonight for the first time I'm getting annoyed... I got redirected with a mission only to turn up at the NEW destination.... Can't hand in the mission. Frustration at level 11.
I think this is bugged for everybody? Or at least I'm seeing the same thing - midmission delivery change == mission can never be completed.
Maybe it's a feature! You're forced to abandon the mission which marks all the mission cargo as 'stolen', so you can sell it to a black market and work on your rep to meet the Dweller.