I found this from reddit: "We received reports that the challenge was not providing its reward upon completion. During our investigation, we found the underlying issue and have now resolved it. Unfortunately, we are not able to retroactively grant the challenge reward for players who have already completed the challenge at the moment. Our plan is to retroactively grant the challenge reward once we have an additional change ready to deploy. This might take until the new year, and we apologize for the inconvenience caused by this."
