How to make Word the default app to open my documents on Mac OSMonterey?

1. Select a document you wish to open with Microsoft Word.
2. File menu > Get Info > Open With: select Microsoft Word
3. Change All... and confirm.

Choose an app to open a file on Mac - Apple Support

That's very puzzling. If you try to open the document in the usual manner, does the same message appear?

In the same Get Info window, under General, what is the document's Kind?

Example: