Well, the bug must be in the Aspose converter, called when you have “enhanced converter” ticked.
In spite of what the pane still says, when you untick it, Scrivener uses its own converter coded by KB, which solves many such problems. There’s a thread about it here:
https://forum.literatureandlatte.com/t/test-scriveners-new-docx-converters/45402/1
Mark