Cannot reroll multiple copies of the same champion shard consecutively

As luck would have it, I have 4 Twisted Fate champion shards. Since Ornn came out today, I want to reroll 3 shards as a cheaper alternative to buying the champion (and I thought it would be cute if all 3 shards were the same). However, when you first click on a shard and open the reroll menu (where you select two additional champion shards to reroll), clicking the Twisted Fate shard again does nothing. It does not add it to the mixture. I can, however, add a different champion shard to the mix, then add a Twisted Fate shard as the third and final one. It's not an issue for me personally, as I can still reroll, but if someone had the luck to only have 3 of one type of champion shard, they would be unable to reroll those three into a champion permanent.