OnlyOffice Documents not being saving Up2Date?

Hi,

i switched that morning on our NC26 from Code Collabora NextCloud Office to OnlyOffice.
We had trouble with the coolwsd, was freezed any processes, only restart the daemon helps.
Installation OnlyOffice and DocServer was easy, small configuration und done…haha…

The problem is the same was actually since 2-3 years exist: after editing a doc, it does not save back to the filestore.

On Git says the developer, it works all correctly. But i mean i upload a exist as example xlsx-file, edit it and grrr, changes not saving.

No other tabs or sessions exist, no other users logged in.
Whats the problem?
Cant see any issues in different logs like php-log/apache-log etc.
Only what i can see, in clouddb.oc_documentserver_changes many lines, where i dont know, its correctly or not or after closed session it must be clean.