Loot Chest Reward Bug Upon Leveling..?

Hi team!

Not sure if this is a bug, but I believe it to be. So, in my last match I leveled Abathur up from 6 to 7. At the same time, my player level also increased from 449 to 450. The only chest I was awarded was the epic chest for reaching the 50 milestone, I did not get a chest for hitting 7 with Abby.

It is my understanding that players receive loot chests upon each level a Hero reaches. Unless I am wrong, I should have had two chests awarded to me in this instance: one common, and one Epic. I'm not too worried about the missing common chest, I am just concerned that there may be a bug when two or more chests are awarded to players for completing multiple milestones in one game.

Is this actually a bug, or is the game working as intended and I am wrong?