I saved a few siphers and purchase a few armor pieces. However, when I went back to Xur, it said the item is still not in collection. I literally have the exotic armor piece equipped and just trying to buy another one from Xur. Am I doing something wrong to unlock the armor for my collection? The siphers are a pain to get and I just wasted 3. None of the armor pieces are unlocked and available in my collection. Help please.