- Is it an InDesign only issue or does the problem exist when you export a PDF from InDesign?
- Does it change when you change the display quality to high?
Why do you prepare a PDF in Word for placing in InDesign. Are you aware when trash comes in trash comes out? Place in InDesign text from Word and style it with Paragraph and Character Styles inside InDesign and export from InDesign a correct PDF.
View > Display Performance > High Quality Display
The only thing I can think of that would cause this is the Display Performance.
In the Preferences go to Display Performance, and in Vector Objects slide it all the way to the right.
Or in the View>Display Performance choose High Quality.