If I click on “insert mode” on the status bar, it has no effect, it never changes to “overwrite.” The help screen for “insert mode” says:
Click in the field to toggle the modes
(except in the LibreOffice Basic IDE,
where only the Insert mode is active).
Looks as if this is my problem, that “only insert mode is active.” What is “Basic IDE?” How do I get something else, so I can use overwrite?