seeking within specific files breaks audio

[Alloyed]

mpv version and platform

Arch Linux, using OS package

mpv 0.22.0 (C) 2000-2016 mpv/MPlayer/mplayer2 projects
 built on Sat Nov 26 20:40:21 CET 2016
ffmpeg library versions:
   libavutil       55.34.100
   libavcodec      57.64.101
   libavformat     57.56.100
   libswscale      4.2.100
   libavfilter     6.65.100
   libswresample   2.3.100
ffmpeg version: 3.2.2

Reproduction steps

This consistently seems to happen to files recorded from OBS-studio 0.16.6-1, when the mkv format is used. Examples attached below.
It's very possible that OBS is spitting out malformed files, but the same files work in VLC and totem so I figured I'd start here.

1. Play video
2. seek to any point

Expected behavior

audio playback

Actual behavior

no audio playback

Log file

https://alloyed.me/shared/log.txt

Sample files

https://alloyed.me/shared/2016-12-18_16-42-05.mkv
https://alloyed.me/shared/2016-12-18_16-37-59.mkv

[ghost]

@Alloyed According to the commit, 3b5777d - this is a bug in FFmpeg. It is creating bad mkv files that isn't marking audio packets as keyframes, or something like that. If you have time, please report the bug upstream (https:/FFmpeg/FFmpeg) so it gets fixed there too. ;-)