Windows 10. The icons of LO (7) documents show correctly when viewing in Explorer in List, Detail View etc.
If in Large or Extra large View, with thumbnail set, the thumbnail is shown but the (small) file icon in bottom right shows a plain folder icon not the icon associated with the file type.
Note: sometimes, if screen redrawing, you get a flash of the correct icon so specific one seems to be overwritten
File Explorer Options (View) are:
Always show icons, never thumbnails (unchecked)
Display file icon on thumbnail (checked)