I faced similar situation. Google brought me to this forum, however, I do not think any of the solutions on this page are correct or complete. I see that this post is quite old but I would still like to share my solution, so that others may benefit from it.
I am using Microsoft Office 2016.
- First, I inserted a text box by going to Insert > Text Box
- Once the text box is on the document, I adjusted its width so that it meets my needs.
It spanned from column 1 to column 2 (roughly speaking, it was as wide as the page)
- Next, I could see the box is covering my text. To solve this, I selected the text box and went to Layout > Wrap Text > Square
The beauty of this solution is that Text Box serves as an independent identity and any formatting changes made else where in the word document will not affect the text box