I am setting Word 2016 as default program (or app, whatever) for opening docx files using "by file type" option in Settings (Win 10 Pro). When I check in "Control Panel\All Control Panel Items\Default Programs\Set Default Programs" what files Word can open, it reverses to Word Viewer as default for docx.
In the new "Default apps", Word 2016 is not even listed as an option for docm, dochtml etc. Windows 10 Settings are so user unfriendly and buggy, it is laughable. Both Windows and Word are Microsoft products, why cant they get along?