I'm Level 10 and one of three objectives which I need to complete is to "Run 5000m with Frozen Scarlett". First, I thought that I needed to wear Frozen's Artifacts, so I did that and ran more than 5000m in Sky Summit, but the mission wasn't completed. Then, I thought I should do it at Frozen Shadows so I tried it again, but it's still uncompleted. I chose Scarlett Fox with all of this. I'm really confused with this situation. Could you let me know how to complete this objective?