The actual folder and filename are encoded? Huh! I use a core WordPress function
sanitize_title() which in turn uses
sanitize_title_with_dashes(). In that later function it does indeed check for UTF8 and encodes them to be URI safe. I never know that! I wonder why?
I use that function to create entry slug, this slug is also used to create the entry file folder name.
It seems is can also do a check for UTF8 and use the
sanitize_file_name() instead to create the entry slug.
Could I get a temp admin account and temp access to FTP so I can test this to make sure the solution will work? The login details can be sent via the contact link at the bottom of the page.