Hi,
When I add a Korean content or Arabic one in Meeting notes for example, I got ????? until I refresh the browser completly (using F5). same issue I am facing if I open the notes later after opening it I have to refresh the browser to read the non-ASCII characters.
Also I am face same issue exactly when I upload file with Arabic name.
Please note that I have MySQL with UTF8 and Confluence is behind Apache Proxy.