just bought 6 champs and can only refund 4 of them

bought all 6 right now with IP (yeah its ip not blue essenze fuck off riot), checked what i bought last and realized i could only refund 4 of them. why not zyra and xerath? this makes no sense.

edit: all 6 are bought from the shop, no shards were used. i HAVE a zyra shard but no xerath shard.