Unfortunately, there is no button in Word to reset the program to its default settings. However, you can rename Word's global template to see if that fixes its problems.

You can reset some Word settings, such as the Word Data and Options keys in the Windows registry. To reset Word to default settings in Windows 11, follow the steps below.

How to Reset Styles in Word 2007. Whether you've inherited a Microsoft Word 2007 document from a previous executive or are editing something an employee created, reformatting the document back to ...

Learn how to change default Heading, Quote, Title font family, size, etc. in Microsoft Word. You can create new style for paragraph in Word too.