I just tried to play an mkv DVR-generated file from HDHomeRun CONNECT. The tuner source for that channel is a 1080p h.264 stream. For those files only there is no audio. VLC shows that there is an audio track (AAC/mp4a) but no audio. Tried different players with the same result. Other MKV MPEG-2 recordings work fine as well (recorded with 1.7.2.3878).
If I look back at older .ts recordings from the same channel, the h.264 1080p recordings have audio. No changes on my end expect going to 1.7.2.3878 and the resulting .mkv container.
Bug?