This is related to
SAK-20290. When grading students, if the instructor presses the back button, it seems to stay on the entry for the previous student, however the comments and submission for the previous student are pulled up. This is easily saved causing loss of data. It's easy to say "avoid the back button" but hitting backspace in some browsers outside of the form fields also creates a back button. Either the back button should be trapped so it can't be hit (as it doesn't do what's expected anyway) or this problem with the state should be fixed.
Demo: (This was done and tested in Chrome, not all browsers treat the backspace button as back button, but should be duplicatable in all browsers)
Many people want this behavior disabled in Chrome but they don't seem to want to revert.
There are extensions to disable but there are also complaints that they don't always work.