Thank you for your reply, I'll try to explain more, because it doesn't solve the problem.
I'm using grade scale not rubrics and I know about the Single View in the gradebook. Most teachers in my school prefer to use for mass grading The Grader Report in the gradebook and after some time go through all student grades in the assignment grading page (your moodle/mod/assign/view.php) where always was a possibility for quick grading (Mark checkbox Quik grading and choose from the dropdown list new grade to change it) and change grade. It the version 2.8 page yourmoodle/mod/assign/view.php a possibility of quick grading doesn't work if grades have been set for the activity using Grader repot and does not show grades that have been set for the activity using Grader repot. Instead of grade is "-"
The screenshot from the last message is showing how it was in the 2.7.2 version
Now The Single view is allowing to do same as previous was allowed on Assignment page View/grade all submissions (yourmoodle/mod/assign/view.php)
Also button <Save changes> is inactive in The Grader Report in the gradebook in all browsers.
Thank you for any help.