Doubleclick is emulated by Babylon and not using native doubleclick events. You can define the delta time between two clicks to be considered a double click. I am not sure this is the solution you are looking for, but it’s one way of fixing it 
The default time is 300ms. Reducing it to 100 - https://playground.babylonjs.com/#TTQ6G7#2 works better. but then you will probably have hard time getting doubleclicks to work.