Hextech Chests

So I've gotten an S rank with 2 different champions. I own both of them, I haven't gotten an S rank before with them, yet I haven't gotten a single Hextech Chest at all. When I hover over them it says "Chest Acquired" yet, like I said, I haven't got a single Chest at all, and when I look at my profile it says I have 3 more chests available. I've been looking around to see if anybody else has been having the same problem but nobody has