I suspect it's because you set AudioPreloaded to 1 in the first event:
If your game has fully loaded once before, it won't trigger event 1 again because loading progress will already be at 100% so AudioPreloaded will remain at 0.
You can ensure all sounds are preloaded whilst the game is loading by ticking "Preload Sounds" in Project> Properties>Startup, so you won't need to preload them manually in the Loader Layout. This is fine if you only have a few sounds to load, but if you have a lot of sounds and only want to load a selection of them to keep the initial load quick, then use the manual preload actions.
You can simplify as follows:
dropbox.com/s/z10homwhvtsrkn6/audioLoader.c3p
Wait until the loader has completed, then preload the audio, then progress the layout when the audio is complete.
I've added some debug text and waits so you can see the progress when running it.