Audio Issues with music in Asset Bundles on Linux/OSX? No playback on some systems

We recently switched to using Asset Bundles for all platforms (Win, OSX, Linux). For some reason, on some OSX and Linux systems, our music audio files simply do not play back. No errors messages of any kind in the log... they just don't play. We've tried OGG and WAV formats, and load types as Streaming and Decompress On Load. For some users, the music simply never plays back; but sound effects are OK.

Windows users have no issues. Also, not all OSX+Linux users have this problem.

Is there a known issue here?