Trying to Open a .dotx Word Template File Opens a Blank Document

Issue: I want to edit an existing Word template *.dotx file, and I am unable to.

What I did: I created a *.dotx file by right-clicking on “This Document’s Style Set” in the Design tab > Save > Save as Type > Word Templates ( *.dotx)

Note: I did it that way because:

1. from an existing there is no “Save As” available (see image 1)
   
2. from a blank document, there is no “save as a specific file type” available to me (see image 2)
   

What I tried: When I try to open an existing Word template *.dotx file by double clicking in Windows 11 Explorer, it opens a blank document with no custom styles saved.

When I try File > Open in an existing Word .docx document, there is no option to open by type, and when I navigate to the *.dotx file location, there are no *.dotx files displayed – only .docx files.

(Note: There is a similar question on 4/21/22 but that solution did not solve my problem)