I encountered a strange new behaviour: When a student completes a course moodles updates the table "0_course_completions". And when it enters a timestamp in the column "timecompleted" the course suddenly disappears from the moodle dashboard.
When I manually set the column to NULL the course is back again …
I don't know when exactly it started, maybe after the last update but it starts getting a problem.
Is this a known bug? We're running Moodle 3.5 (Build: 20180517).