I have all my suit modes on lvl 12, so I have completed the mission for each and I should have got 5000XP from each. Yesterday it showed me 10/11 Levels. (This was in version 1.2) Today it shows me that the mission is completed, but I didn't got any XP. (This happened after I downloaded the patch for version 1.4)
It's good news (my PC is breaked, so I can read only news) - I stopped on 8/11 (stealth) and 9/11 (armor), however I've got 12-12-12.
You are upset about 15k XP? O_o About 30 minutes of play, so don't be upset - I think that you already have about 700-800 thousands of XP, so these few thousands are not a problem for your XP
You mean the skill assessments "Form tetsudo" and "Invisible War"? Apparently those are bugged and you have to get all 12 levels in 1 game or something...