A BUG?or something else..(Hextech free chest on mark S- or higher)

It is new season and you know that if u get S- or higher on champion you own u get free hextech chest.You can get one chest for one champion only at once.It is new season so it restart .I got 2 times S- rank and i didn't get chest so i want to ask somebody is it a bug or something else idk?