Inserted comments no longer highlighted on screen

On my previous computer, if I selected an area and then did Insert / Comment,
Word would highlight my selection in yellow on the screen. My current
computer does NOT highlight the selection. Both computers insert the tiny
little parentheses with initials in the text to indicate the comment, but
these are very hard to see. So far, I have not been able to find a place to
customize how comments appear. Does anyone know how to do this? Or is this a
bug of some sort?

I strongly prefer to NOT display the comments as balloons because it takes
up too much space on both the screen and the printed page. The highlighting
worked well before, and I would like to find a way to get it back...I work as
an editor, and the main way I communicate with my authors is through these
comments. Can anyone help? Thanks!