We upgraded to Moodle 4.0 about a month ago and have been having issues with our students failing the quiz but getting a course completion email. I see this ticket that references something similar but it was for the badge and that issue was corrected.  Our courses are set up to complete based on activity completion of the modules and a quiz. The completion for the quick is to receive a passing grade. Even though the quiz module shows a red X in the box, a course completion email is still sent out and shows complete under my courses tab. This was all working pre-update and is now causing a lot of confusion. 

Running Moodle 4.0.1+ latest release

 Similar issue 

1. MDL-74478

To Repeat this. Build a basic course. 

1. Set enable completion to yes
2. Add a course module like a book or H5P interactive content
3. Add a quiz and set the completion criteria to must view, must receive a grade, and must receive a passing grade of 10.
4. Set up a restriction on the quiz to be restricted until the previous module is completed
5. Add one True/False question and set the answer to True
6. Take the course as a student and fail the quiz. 

An email will be sent out that the course was completed and in the dashboard and my courses page, the course will show 100% complete even though the quiz in the course says Done Receive a grade and then failed. It will show a red X.  If you have another module like a certificate after the quiz, it will also be unlocked. 

The completion criteria should only look at the grade if passing instead of receiving a grade if a passing grade is required.