I noticed that when you start Armatus as a bounty and decide to continue past the first round, you will lose the first round's reward and only keep the rewards from round 2 onwards after retruning to Deimos. I've ran this bounty twice and both times this is exactly what happened. First time lost a ruvox glove and second time lost a neo relic.
The first run this happened, I was host. The second run I was client.