On second reading of your issue :
Make sure you are providing the correct audio format for your music and sound files (m4a for safari).
What is the actual size of your sound/music files ?
Perhaps it's not loading because the files are too huge and use all the memory of the phone.
During your preview over LAN you can still look for errors your browser, and see what the console is returning as an error and provide it in this topic to give clues at what's happening.
Finally, possibly consider to share your capx, have other people testing out the issue on their own device to see if it reproduces.