I'm confused. What has been happening is I import MKV's, use "Get Movie & TV info ..." to lookup art and metadata and then hit "Use this data". A JPG cover art field and a JRiver sidecar file would get created in the movie folder along with the MKV.
Now I just get the cover, but the metadata is magically present in MC with no sidecar. Where are the tags stored? I didn't think MKV's could imbed tag info like MP3's?
If the tags are stored internal to the MC library, why was I getting sidecar files before? This behavior changed without an update - I was on 17.0.75 before and after - didn't change any options.