Problem with onlyoffice excel not loading / outdated document

We have a random and recuring issue with Onlyoffice / Nextcloud installed on a private server.

  • Some documents are marked “Modified : (many) days ago” but we do changes on files almost everyday.
  • If we download from panel link the document on local, downloaded version is indeed from many days ago and we lost the last changes made.
  • If we open the document in browser, most of the time there is no problem to work on it and it is up-to-date.
  • It happen that we cannot load anymore a document: cannot load at all or is stuck at 83%. It means that if we use the download option in backpanel, the downloaded file is from 21 days ago. Only option we have is to succesfully load the document in onlyoffice and download the document from there, then the download is up-to-date. But we cannot finish loading it.

So it is a big issue as our current document we potentially lost 21 days of work and data on it and we cannot open it in browser.

What is the solution there?