Hextech chest skin disappeared

Before purchasing some Hextech chests, I already has the Talon SSW skin shard in my loot. I opened one of the chests and got it again but no 2 appeared on the icon which I thought was strange. I had never had a double before so I thought maybe that's just the way it is. Then a few days later I got another double, this time a Taric skin (pool party I believe), and the two popped up on the skin icon. Just wondering if this has ever happened to anyone else.