Is the "Challenge Accepted" achievement broken?

I'm having trouble getting the "Challenge Accepted" achievement (on Xbox, but this might be on other platforms too)

The text reads:

Challenge Accepted

Completed level 1 of all non-level-specific challenges with a single character

I've done that - every non-level-specific challenge shows at level 2 or higher (most are maxed out) but I still don't have the achievement.

1. Am I missing something?
2. Is this achievement glitched in some way?
3. If (2) then is there any way to fix it?