It would be nice to have the same .docx that was used for reproducing the issue reported. On my side, I have tested on XWiki 17.10.7 and 18.1.0 with LibreOffice 25.8.6.2 and I didn't notice any difference between XWiki 17.10.7 and XWiki 18.1.0. What I have noticed is that, in both, the color-format (Font Color and Character Highlighting Color) is are not kept after importing and regarding the Fonts - some are kept and some are not kept or transformed when 'Filter Styles' is ticked. If 'Filter Styles' is not ticket than both, the color-format (Font Color and Character Highlighting Color) are kept.
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