cannot get tabs to work
Tabs aren’t available in HTML documents, that’s because tab tags have been removed from the HTML specification many years ago, not because of something wrong with LibreOffice.
If this isn’t happening in an HTML document, put more effort in explaining the situation.
This is a docx file. Nothing to do with HTML. This is a new problem in v. 5.3.2.2.
You should have given the version and document type information in your first post, that would have spared me the trouble to refer to HTML. When it’s a problem (bug) in version 5.3.2.2, you should file a bug report or post a comment in an existing bug report so it gets more attention.