See attached test file in format .DOCX plus screenshots from MS Word (version 2010) and LibreOffice 6.2.8.2 (I tried LO 6.3.4.2 as well and the issue is reproducible there as well). The same problem exists if saving the test file to .DOC in MS Word and opening this .DOC in LibreOffice. Note that the dialog window displayed in the screenshot from MS Word shows the information related to "Chapter 1, level 2" (unlike LO Writer, MS Word doesn't keep highlighting the selection when opening the numbering and indentation formatting dialog box, but exactly the same content was selected as on the screenshot from LO). As visible there, MS Word shows correctly that the paragraph is at level 2, whereas LO Writer shows level 1 (as observed from the paragraph numbers in the text as well).
Created attachment 156751 [details] Test file in .DOCX format allowing to reproduce the issue
Created attachment 156752 [details] Screenshot from MS Word displaying the test file
Created attachment 156753 [details] Screenshot from LO Writer 6.2.8.2 displaying the test file
I confirm the bug with LO master 6.5+. There are similar ones like bug 95495 or bug 129531 so this is probably a duplicate. But, we may keep it until confirmed.
Numbers weren't there before, but in 4.2 and 4.3 they appeared fine. And since LO 4.4 they are wrong as in 6.5+. So I set regression.
Regression introduced by https://cgit.freedesktop.org/libreoffice/core/commit/?id=c99f264be5eaf481f88606e2606c34170675c1b4 which is already reported in bug 94326 *** This bug has been marked as a duplicate of bug 94326 ***