There is an issue in Moodle that occurs when a student uses their Grades link to access their course grades. The course homepage switches to the Grades page but only stays open for a split second. The activities and scores disappear and the student is left with a blank page.
The issue is due to the Proctorio plugin in the Google Chrome browser. It does not happen in other browsers. The solution is to (temporarily) turn off the Proctorio plugin OR use a different browser to view your grades.
Turning off the Proctorio plugin in the Google Chrome browser
Go to the three dots in the upper right corner of the browser menu bar; click them to expand the menu.
Choose More Tools; then choose Extensions.
Locate the Proctorio plugin block and turn it to OFF. When you return to your Grades page the screen will stay steady for you to view your scores.
NOTE: Remember to turn the plugin back on before taking an exam the requires the Proctorio plugin.