Ideas
Yeah this happened to me when I did The Headline and when I did Muy Manual. With both of them I did it solo, had lots of tries cus they were challenging, shut it down, celebrated and sighed great relief. Then, I looked at the challenge on the map and it was entirely incomplete, not one goal on the thing checked off. And I definitely clicked through the replay and win screen, didn't redo or cancel or something. I redid The Headline and shut it down, and it stuck that time. I'm currently annoyed how long it took me to do Muy Manual and don't wanna try again right now. Super annoyed. This is my least favorite bug so far!
I also did some co-op challenges with my friends. For instance, C-Line. We did this one co-op together, my friend was hosting. And when I got back to solo party, I realized this one was incomplete. I didn't know if this was a bug or how co-op worked. Maybe the host is the only one that gets a completion? Or co-op challenges are completely separate?
Please fix these bugs or add some clarity for folks on how this is supposed to work. The solo challenges definitely seem like a bug for sure. I can share videos if you want, but I promise I shut them both down, got the replay and completion screen, then... sorrow and anger.