This has been happening to me from day one. I have tried restarting the console completely, along with dashing out, and have had mostly poor results. Sometimes my armor/loadouts/emblems won't come back until I have leveled up again, in which case it says I've unlocked a million different things. I too am very disappointed by this, it's very frustrating. I hope a solution is found promptly.
By the way, not only are the customizations that I have unlocked with XP disappearing, but the DLC armor from preordering and buying the console are also going away. In fact, I have YET to see the forest armor show up on my list. I have redownloaded it and everything, still no results.
