Forum Grading Does Not Respect Separate Groups Filter

Setup Login as an 'admin'. Create a course. Create 2 users, and enrol as 'student' to the course. ('Student 1', 'Student 2') Create a group ('Group 1') to the course and add 'Student 1'. Create a group ('Group 2') to the course and add 'Student 2'. Create a forum activity with 'Separate groups' in 'Common module settings > Group mode', and 'Whole forum grading > Grade > Type' set to 'Point'. Test Navigate to the forum. Choose 'Group 1' in 'Separate groups' dropdown, and click 'Grade users'. Confirm , the grading screen is for 'Student 1', and number of student is '1 out of 1'. Click close. Choose 'Group 2' in 'Separate groups' dropdown, and click 'Grade users'. Confirm , the grading screen is for 'Student 2', and number of student is '1 out of 1'.