A family of Microsoft word processing software products for creating web, email, and print documents.
Looking at your example, the Normal style contains shading which cannot be removed via the user interface. However, running the following macro did the trick:
Sub RemoveCharacterShading()
'Stefan Blom, MVP, March 2020
ActiveDocument.Styles(wdStyleNormal).Font _
.Shading.BackgroundPatternColorIndex = wdAuto
End Sub
You will also have to select the text in the document and remove direct font formatting (press Ctrl+SpaceBar to do that).
Here is a screen shot of the result: