In the past and more recently ,there have been complaints about getting the level but not the reward.

So I was trying to get the last level reached the exact number of points, got the tick ,but nothing else. 

Time was short so just sent out one slayer, was trying for1 unit, it picked up 11 units, when it returned the reward dropped.

Seems to confirm rounding errors,and the need  to go past the target given to be sure .