Hi' I've trouble with a new Word version:
Microsoft 365 MSO (16.0.14326.20706)
If I open a generated docx with office 2019 is correct, but if I open the docx with that version the summary jump from 9.16.3 to 12.1.1. Chapters name are correct.
I try with phpdocx 11 and phpdocx 12.5.