Could be just me since I haven't seen any similar posts but something changed between the 31st March and the 1st April nightly - i.e. with 31st March le12 nightly I have video + audio but with 1st April nightly it is only audio (my Samsung tv reports mode/resolution not supported).
From what I have observed it is only happening with HEVC videos (720p/1080p/2160p) - by turning off DRM Prime fixes the problem and the video is shown along with audio.
As I said it could be something in my settings but I don't recall changing anything that would have this effect and simply reverting back to the previous nightly build fixes the issue then I believe that it may be more widespread.