A family of Microsoft word processing software products for creating web, email, and print documents.
If this problem is occurring in all documents in Word, not just one specific document, try performing this process to resolve the problem.
Before performing this process, please log into your Microsoft account on this link (https://account.microsoft.com/services/) and check to ensure your Office licence or Microsoft 365 subscription is listed correctly on your account.
Open the Settings App (gear icon on your Start Menu)
Go to Apps - Installed Apps, then scroll down to find Microsoft Office
Select that and choose Modify - Online Repair
That should fix any issues with your Office Installation.