Megastack to backpack reverts to max stack size

This seems to happen with any stack of items that are over the server's set "max stack" I lost 4k stone as I went to put the 14k stack into my backpack and the 4k vanished.

Side notes: If I have a max stack of 100 of an item and a stack of let us say 94 and I try to pull the 100 out it will give me the 94, if you have multiple stacks of NOT the max stack it will try to combine the small ones into the max before it will let you right click them out of the backpack UI (Our UI only). It will also not let things go to the "Hotbar" even if all other slots are full.