Changes to a Collaborative Document in ONLYOFFICE not saved or visible in version history

We were editing a collaborative document with a table in ONLYOFFICE, and multiple users could see the changes in real-time. However, these changes were not saved and do not appear in the version history. What could be causing this issue?
ver. 9.0.3.1

Hello @Yuri

Do I understand that all users closed the document after editing?

It’s possible that not all users closed the document after editing. Could this be related to the issue?

In that case the document is not saved to the storage, but the changes are stored in the editing service. Do I understand that by “these changes were not saved and do not appear in the version history” you meant that the whole version does not appear in history? Or it is related to the specific changes in the version that appears after save?