touchesEnded() is not called when user tap the touch screen frequently

Hi All,


I am following the following documentation to implement a multi-touch app:


https://developer.apple.com/documentation/uikit/touches_presses_and_gestures/handling_touches_in_your_view/implementing_a_multitouch_app


The problem is when I touch the touchscreen fast enough with all my finger on the screen, touchesEnded/ touchesCancelled are not called sometimes. The UIViews are not removed from the superview and left unwanted UIView on the screen. For example:


https://imgur.com/a/QHXIw


It is critical to catch every single touch event for my application. Is there any method to solve this problem?