Should mkv remuxing be avoided for ts recordings with mixed audio

Yesterday I recorded Dr Who and then remuxed the ts file to mkv to add to my library. The file starts with a few seconds of stereo audio and then switches to 5.1. On the Vero, playback of the mkv file dies at the audio format transition, with a still frame on the screen, and playback goes wrong in other ways with VLC (video continues with no audio). Playback of the ts file is fine and my AVR switches from stereo to 5.1 PCM seamlessley.

Is this a potential bug with mkvtoolnix or is it a limitation of the mkv container? Easy workaround is not to remux these off-air ts files, but curious if anyone knows what the root cause is.

I’d suspect limitation but if you really wanted to change the container you could just use the split mode output to trim off those first few seconds.

here is a link to the pre-titles sequence, the audio switches to 5.1 a few seconds in. Although I split the mkv by remuxing from the source ts file, the main program mkv is stereo according to Mediainfo, and plays with no audio. Anyway, just as easy to keep a ts file in the library for now.