For some users the value of "timeenrolled" in the course_completions table is "0".

If the user is enrolled in the course and completes it before the cron job runs, the "timeenrolled" value will be set to 0. (the first row in 8.png)

If the user is enrolled in the course and completes it after running the cron job, the "timeenrolled" value will be set correctly.(the secound row in 8.png)

applies to: scheduled task: Completion mark as started (core\task\completion_daily_task)

To reproduce:
1. add new course
2. enroll some users in the course (1.png)
3. check the course_completions table - is empty for the course (2.png)
4. complete the course for one of users (3.png)
5. check the course_completions table - for the user, the value of "timeenrolled" is 0 (4.png)
6. run cron task: Completion mark as started (core\task\completion_daily_task) (5.png)
7. check the course_completions table - for the another user, the value of "timeenrolled" is correctly (6.png)
8. complete the course for another user (7.png)
9. check the course_completions table (8.png)