display map on mobile

[sundussabbah]

Hello everybody,

I want to make a mobile application that display map with feature layer

the problem is that map loading and rendering is bad

as in the image up when I pan the map part of it will disappear until I make some panning ( which mean the internet connection is not the reason of the problem )

and I added a feature layer on the map but the problem is that the symbols of that feature layer displayed only in the right half of the screen and when I pan the map and reach the middle of screen it start disappear , see the picture below:

so please help me what is the problem? , did I miss a specific meta or parameter ??