I had this problem before. But not anymore. I keep the sound in the sound folder and the music in the music folder and it works like a charm. The sound in the sound folder is downloaded the first time they are played while the music in the music folder is streamed and that is why you see the difference in the delay.
I start my game with a loading layout and after the loading is complete I go to the main menu layout.
Then I Usually start by putting the play audio event before any other event. Like on collission wih X play audio followed by the other events like damage or other code.
I also delete all other file formats of every sound, only keeping the .ogg files.
In the new version of construct I think preload sound is forced by default and no preloading is required. But correct me if I'm wrong.
If you are experiencing this while testing on network or in browser on your android device then I think this is the problem. I also see this delay when I test the game thorugh my network. But as soon as I compile and wrap it with CocoonJS the delay disappears.
So if you haven't compiled it and wrapped it yet. Try that and see what you get.
This woked for me when I made this simple android game:
https://play.google.com/store/apps/deta ... appz.dropz