An MKV file is only as good as the hardware playing it. Because The Way of Water is a heavy file, ensure your setup is up to the task:

The Way of Water features a rich soundscape. MKV allows you to switch between original English DTS-HD Master Audio, descriptive audio, or various dubbed languages seamlessly.

MKV supports "soft" subtitles (which can be turned on or off) rather than "hardcoded" ones that are permanently burned into the image.