A few tries with my mkv: some of them displayed in top-bottom while some others were good: the reason: missing the flag in the mkv.
To add it: open the mkv file in mkvtoolnix: select your video stream: on the right you have “video properties”: the stereo should be at number 13 for MVC 3D (both eyes in 1 block, left first)
For the movies with right eye first: it looks very strange (but that’s a known problem for this release).
Nice improvement for the vero 4k.