I sent my crew out on some 33 - 40 Underworld trading missions for companion gifts. All my crew is back, but the missions are no longer available to me. Only one repops, and it is for underworld metals. I have ran it, and I have stepped down a tier and ran those, but still no missions for current level. Is there a cooldown or something?

Ok, Nevermind. I understand now. When you reach a new tier, you don't get them all at once, and that is what I was having a problem with. Didn't realize I had went up a tier.