We are running Moodle 3.11 with Marking workflow and Turnitin features enabled in assignment settings. We are also using separate groups in our courses for the many cohorts. 
We noticed recently that when a teacher within a Moodle group releases grades for some students, all of the students in that group can see the results, even when their status is set to 'In marking' or anything other than 'Released'. This happens when the marking status is processed in bulk or when quick grading is in use. To reverse this, we've had to select students that were incorrectly released and then update their grading status. This is inconvenient and a huge concern as students should not be able to see the grades before they are meant to. 

Sorry but I am unable to create a new ticket even after going through the many bug reports to try to find something that matches what we are experiencing. The fact that students are able to see grades before they are being reviewed by the teacher is causing a whole lot of problems for us. Please review this as I suspect that the Marking release feature is not behaving as it should be. Thanks.