@Maybelle_S 

I have a MAC.  To be clear, this is a problem I encounter when typing into the Compose Box here... Not really in Word but I suppose you're indicating that the Word setting could be causing problems here? Composing and copying in Word and pasting here has been my workaround tip. 

My MAC Word Options:

Word>Preferences>Edit> Screenshot of options attached.

       I do not see Use the Insert key to control overtype mode

       I do see Use overtype mode and it was already not checked.