DOCX saving compatibility problem

Aspose.Words 9.3.0.0
When I open DOCX file and than saving them I can see in Office Word 2010 that some features was disabled and it can convert file to new format. Can I use any options to persist these features while saving file?

Hello

Thanks for your inquiry. I cannot reproduce the problem on my side.
Could you please try specifying OOXMLCompliance:
https://reference.aspose.com/words/net/aspose.words.saving/ooxmlcompliance/
Here is code example:

Document doc = new Document(@"Test001\in.docx");
OoxmlSaveOptions opt = new OoxmlSaveOptions(SaveFormat.Docx);
opt.Compliance = OoxmlCompliance.Iso29500_2008_Transitional;
doc.Save(@"Test001\out.docx", opt);

Please let me know if this helps.
Best regards,