My HTML5 game need to be start twice to work, is it normal?

Hey!

I don't know why, but when people try to test my HTML5 game, they have to start it a second time to work, first time a lot of object didn't appear randomly and make the game impossible to play.

You can try by yourself :

luminous-speculoos-a8a4a3.netlify.app

Is it "normal"? I don't know if it's server side, or if it's my game, since it work very well when I export to windows.

Any suggestion to fix that? Maybe add some kind of wait at the launch?

Thanks a lot!