When you have 10 Ascendant Shards and 50 Prisms in your inventory, every additional shard and prism gets moved to the postmaster ,which is fine (although you should be able to carry way more materials, but whatever). Now imagine you have 50 Prisms and 10 Shards at your Postmaster, and the postmaster is full. Logic would tell you that every item you get is lost because your postmaster is full, right. Nope. If you happen to get a Legendary engram and a umbral engram, both Prisms and Shards get deleted!!! and are being replaced by any new item. WTF is this. It only happens to shards and prisms. Fix this shit asap Bungie, whats the point of collecting materials if you simply replace them at the postmaster. Just lost 10 golfballs and 50 prisms for no reason. -blam!-ng hell. That's -blam!-n ridiculous.