OnlyOffice: "an error has occurred while opening the file" and lost one day of work

Hello, on a specific file, OO now refuse to open:

The problem is that if we download/access that file from the desktop client, we have a old version,n and we lost the work of a day.

Is there a place where OO stores temporary caches of the files we can retrieve? The NextCloud version history is empty and, as said, the version we can download is one day old, it is not the latest version of the document we did work with the whole day…