Kahn reporting shows "not started" but also shows "minutes" are non-zero

I'm confused why when I ask for a CSV report on my students activity I see every single assignment video and excersize and Quiz has the entry "not started". Yet the webpage for activity shows some minutes spent on varied assignments and many lessons are marked as "proficient". I can't square those two observations. I have a theory that it's possible I redundantly re-assigned some units to all the students when I was adding a student. Maybe that could have wiped out the records of completion? I realize that "not started" actually is a misnomer and actually means "not finished". So maybe if my student is not finishing a video or not finishing an excersize this is causing this? If so why would they be marked as proficient?