Highlighting words while editing

Very recently an unwanted change has happened while I am editing text in Word. It used to be that as I selected a word to correct or  delete, a temporary light blue highlight would show what I'd selected. In the past couple of weeks, instead a larger grey and totally opaque highlight obscures the word making it a matter of guessing whether I have selected exactly the text I want to change. For example if I intend to  italicize the word, I may have missed a letter or included part of the word before. This is not happening in other applications such as Adobe Acrobat or when I select text on a website. 

I am using Mac OS Monterey (12.1) and Microsoft Word for Mac 16.57 (Office 365 subscription)