Steps:

1. Teacher adds assignment, allows for additional attempts open manually, specifies a grade to pass, specifies completion criteria - "student must submit" and "student must receive a grade"
2. Student submits assignment.
3. Teacher grades attempt , gives a failing grade and re-opens another attempt for the student.
4. Student visits assignment and sees completion criteria:
   1. "To do: Submit an assignment" - THAT IS CORRECT
   2. "Failed: Receive a grade"  in red - THAT IS INCORRECT AND CONFUSING.

In fact, at least in some situations (after 2nd and later attempts?) student can see their grade in the Gradebook, and on the Assignment status page, even though another attempt is required/re-opened. The grade is a failing grade; however., this should not be relevant here at all. Interestingly, when teacher changes the assignment "grade to pass" value to zero (i.e. no passmark), the completion status changes to "Done: Receive a grade" - which is correct..

Thus, it would appear that somewhere the "passing grade" condition may have been applied / included wrongly instead of the mere "receive a grade" condition.

The problem affects BOTH Moodle 4, and also Moodle 3.11.9 (although in Moodle 3 Assignment's completion criteria do not feature a "Require a passing grade" condition at all, so the "grade to pass" should never have been considered for reporting the assignment completion status..).