WebGL loading so long

My game download finished , it will spent around 2~3 min for preparing then only can load in the game.
what case make it like that ?
is’t my server side problem or miss some step in build setting ?

This is the same issue I had for my game test using WebGL. I haven’t resolve this issue yet.

And I don’t see the progress bar too. I don’t know how to activate the progress bar. Any idea?