Running fullscreen from icon on homescreen

I develop an app with a Leaflet map panel width a sidemenu. The app runs fine in all browsers and native in IOS and Android devices, except…
If I made available to put an icon on the homescreen and toen start the app from this icon on the homescreen of my IPad I got a fullscreen blank.

Does somebody why this happens… or even better has a sulution for this…
Thanks in advance