MyCloud 3TB - stored .MP4 video files recognized as music files in Samsung Smart TV

Network router Cisco Linksys E2000, product WD MyCloud 3TB, FW: 2.30.165, Twonky vers.: 7.2.9-13, TV Samsung UE55H6470SS with latest FW 2860, Windows 10 fully updated.
After purchase of new MyCloud, I transferred some testing files to Public + Private directories. My TV and also the online admin page of WD and also the online Twonky Server admin page show some video files (.mp4) as music files and it cannot be played via DLNA on my TV. But there are some .mp4 files which are recognized correctly also!
Tried to rescan and rebuild the database and restart both in WD admin page and in the Twonky admin web page several times, as well as (systém) factory reset - did not help - there are still some video files registered as music files - while there is no music file in MyCloud yet…

it could well be the encoding format of the video files causing the issues.

MP4 is an ambiguous extension; it can be video or audio.

Many times, simply changing the extension from MP4 to M4V (for video) or M4A (for audio) will correct the issue. If not, It has something to do with the metadata atoms stored in the file. An atom / metadata editor will need to be used to investigate/correct that.

Changing .MP4 to .M4V (for video) didn´t help, neither renaming the files… SOME video files are still recognized as audio instead of video

Couple of suggestions. Use a metadata editor like Mp3Tag to remove or change any of the metadata the mp4 video file my contain. Use a program like Handbrake to reencode the video using a different MP4 codec encoder. As indicated above you could have an encoding issue. A few times when the My Cloud Twonky DLNA server incorrectly categorizes a MP4 video as an audio file, reencoding the video using Handbrake typically solves the problem (for me).

Returning the MyCloud device will solve the problem for me… If it does not work properly, it does not work…