Please bear with me, I am very new to Moodle. When using the gradebook (with editing on or off), text appears as the mouse is drawn over the grade cells. Text appears below the cell with the student name. This text remains after the mouse has moved on. Cells that have not been moused over appear fine.
After a very short period of time, the gradebook is nearly incomprehensible. (image below). The black lines are student numbers that have been redacted.
Our office of information technology says this is a "bug" in Moodle and offered no help resolving the problem. Any help that can be provided is very welcome!