Noticed lately when you select the mercenary AA exp as your reward. A lot of time it says 50% of a merc AA . Had chosen that on some of my alt accounts. It only gave about 10% exp towards a merc AA. Instead of what the reward said. Believe it was working before all the recent changes to overseer.
The reward window is showing 4x times what you actually get. A dev has confirmed that what you actually are receiving is what is intended.