Swipe up is not working but swipe down is working in iOS Application

Hi All, 
I am working on iOS application , i do use on screen function wPropertyY to set the screen on y axis, but on another screen this function is not available, so i used the Swipe (start x, start y, end x, end y ) function. This is the Function that is not doing anything but it is passing on the Testlog. to see the values please see this function. by the logic it should scroll down the screen.
 Mobile Screen

This function works successfully but for the swipe down the screen. Please see the values in the image


Note: if it is working and swiping the screen for swiping up it should also work