Bug conversion word / onlyoffice with bookmark

I find an issue during conversion between word and onlyoffice.
When a document contains a QuickPart object Title whose content is assigned to a bookmark, then after opening and saving in onlyoffice, there is an error opening the document in word.
For example the file [Word Before OnlyOffice.docx](https://nextcloud.intra.gresi21.fr/s/gN2RBtnMb2Qjrit) is correct, but the same file just opened in onlyoffice [Word After OnlyOffice.docx](https://nextcloud.intra.gresi21.fr/s/nogJqzgWCjKM6n7) an error occurd on word opening

Report a bug
Document Server version: OnlyOffice 7.1.2 on Nextcloud 20.0.8
Intallation of the Document Server (docker)
OS: Debian

Thank you for your feedback, we have tested the files you provided, and we could not reproduce this issue on “6.4.2” version, please update your Document Server to the current version and check it.