Not all devices support 10bit HEVC playback out of the box.
: High Efficiency Video Coding (HEVC) allows for significantly smaller file sizes without the "blocky" artifacts common in older MPEG-2 DVD encodes. 10-bit Depth Babylon 5 - Complete Series - HEVC 10bit DVDRi...
Here is a review of that specific release, covering the video quality, the technical encoding, and how it compares to other available versions. Not all devices support 10bit HEVC playback out of the box