Server Version#: 1.43.0.10389
Player Version#: 10.30.7.4190
All players probably exhibit this problem; not any in particular.
Pretty simple to explain. It defaults to the commentary tracks just because they’re stereo vs. the mono actual default track. It’s been reported years ago already, both as a bug and as a feature request. I see this as a clear bug.
For comparison, Emby defaults to the right one:
