Hi,
On a 20.0.9 NC instance, since its latest update, 6.4.1003, Collabora Online - Built-in CODE Server fails to save OpenDocuments.
Sometimes it’s a message saying “Document cannot be saved to storage, Check your permissions or contact the storage server administrator”, sometimes there is no message but when the document is opened again, it’s empty!
Reverting to the previous version, 6.4.806, found here, eveything’s back to normal behaviour!