So apparently claiming the reward at the end of a path occasionally yields nothing. How I got mine bugged: Already claimed primes from vanguard & gambit paths. In the midst of a control game completed mid level bounties to finish the path. Claimed the prime rewards. No prime o bright dust rewarded. (I may have waited too low before resetting the path though I wanted to go back to the combat asap) So just beware. At least wait for the game to end if you don't want to miss rewards.