Sometimes your merge template can contain a formatting switch that causes unexplained formatting, such as bold text, font size changes, or italicized text.
In the merge template document, remove the formatting switch located in the code. ( \* mergeformat ) by finding it and highlight and delete. You can also do a Find\Replace.
Note: You must save the document with Print Field Codes on (press Alt+F9) so that you can see the code.
go to the template
you can see styles at the top
one of the set of letters is selected
right click and choose to update the normal template