I used Handbrake 9.3 to encode some h264 .MKV. Subtitles **bleep** fine in VLC media player!
I re-encoded the same files using the newly released Handbrake 9.4 and the subtitles are fine!
To the WD devs, you could replicate that issue by doing what I did. Use Handbrake 9.3 to create some .MKV that have faulty subtitles under 1.01.11.
Please fix this subtitle issue!