But, isn't WebDav something standard ?

To check if the URL I specified is correct I tried to open it in a browser. After it asked me for the credential I got this error : "Sabre\DAV\Exception\NotImplemented There was no plugin in the system that was willing to handle this GET method. Enable the Browser plugin to get a better result here."

Could this explain why Joplin manage to send the data, but not retrieve them ?

Julien