Unlike Fiduswriter.com, my local instance of Fidus Writer has this unusual display of the .docx and .odt options in the menu for Export (attached). It doesn’t affect the functionality but thought I should note it.
True, this looks odd. It happens when you copy styles as it cannot use the same document for multiple styles. But we should always be able to display the same name, even if the filenames differ.
Thanks for the explanation. As I said, no problem with functionality - just an observation.