S- Grade, "Congrats" Screen Shown, No Crate Given

Exactly as said. Hit an S- grade on playing ZIlean support. This champ was fresh as in no previous crates were awarded to this champ yet this season. When the game ended, I was given the "congratulations screen" offering the crate. Went to the Loot Section to open the crate, and there wasn't one. What gives?