The only sound sets I can get to play through the Online Player are Dungeon Depths, Storm, Witchwood, Blaster Battle, Chess, and Casino. All Moods and sounds that I tested in those sets work, but no Mood in any other soundset will work. Elements in the non-functional sound sets won’t play, nor will any global one-shots (even when tried from a currently functional and playing soundsets).
It doesn’t show playing in the Master (no sound bar movement) and the image doesn’t change in the player when trying to activate a Mood in a different Soundset, it just continues to play the previously activated Soundset. If I go back to the original Soundset in the Master, it shows the animating volume bars. I gave it minutes (while the soundsets that work, worked with practically no delay on the first use), and it isn’t downloading anything to the cache during that time.
Unrelated, but shortly after activating the Chess soundset, the Player froze and just started a half-second loop.