Challenges character unlocks

When my account was level 6 I got Reyna for completing her challenge (50 assists), however, when I got to level 8 and completed Benedict’s challenge ( win 5 matches as a peacekeeper) I didn’t get him even though it showed me I cleared the challenge, same happened with Phoebe, when I got to level 10, I unlocked Benedict, so I guess the alternative challenges unlocks are bugged.
I know other players do get these characters after completing the alternative challenges, but I didn’t.

I’m having the same problem with Kelvin