When I open the Metadata panel for a video, the following properties appear as editable, but after I click Apply, they are not saved:
Author URL
Conductors
Directors
Encoded By
Initial key
Mood
Producers
Publisher
Title Subtitle
Writers
I don't know if the bug is in them appearing as editable, or if DOpus can edit those properties, but it has a bug in doing so.
FWIW, the test video has no subtitles, but Title Subtitle is displayed anyway.