Challenge Defeat the Shaper Conditionally not met, but it was completed for Feared

I still need to complete the challenge of killing Shaper while the Maven witnesses the encounter, but I can't (without first running the Feared) because my Feared progression thinks I already have witnessed Shaper.

I think this occurred about a week into the league (when I first killed Shaper), so it may no longer be an issue. I killed Shaper a few times, but intentionally did not have it Maven witnessed (to make it easier). I then went to kill him with Maven witnessing for the challenge when it wouldn't let Maven witness the fight.

Did you do an Uber Elder witness? That would cause this.