So I'm just starting to use DOffs, and they've completed a handful of missions of different categories successfully. All good so far. But I don't see any of the XP earned on the Overview screen. The only stat that shows anything is Diplomacy, everything else is 0/2500. Is this normal?
When you start a mission it lists the rewards for the missions. If you mouse over those symbols you can see which type of commendation XP it gives.
On the list of missions on the left, they are divided into categories Diplomacy, Military, Colonial etc. Most missions only grant the commendation XP of their category but a few grant from their category and another category, I don't think any Diplomatic missions do this.
So if you only do basic Diplomacy missions you will only get Diplomacy XP
You also only get the XP if you succeed in the mission.