Do you use assignments in Canvas? Students are normally notified of new assignment grades and comments immediately, which means one student gets their grade first, and another gets their grade last, sometimes with many days in between. By “muting” and assignment, instructors can delay these student notifications until all submissions have been graded.
To deliver grades back to all students at the same time, mute an assignment while grading and commenting, then unmute it after grading is complete.
See the Canvas Guides: