UK English compiles to US English in odt & docx

I have a UK system (Win 10), have set Scriv to a UK English dictionary, and use UK English as a default in LibreOffice. As with some others using Macs, if I can convert to doc or docx, it suddenly transforms to US English, resulting in LibreOffice being underlined in red as if wrong.

The solution for Macs is to find the “advanced converters” and untick that box, or something (it works, apparently): where is this option on the Windows 3.1.1 version, or is there something else I can do?


Update to the above:

For ODT format, options > sharing > conversion tab > export converters, then selecting ODT from the dropdown menu, and changing it from “Aspose” to “Scrivener” works (for me). That is, an odt format document is produced which maintains a UK setting in LibreOffice, as originally used in Scrivener.

For the DOC option, changing Aspose to “RTF-based” does not work, with the resulting docx file opening up set to US spelling and therefore showing UK spellings as “incorrect”.

The link to the previous enquiry for Mac users, who had more success in terms of response than I have here: