Play and Pause are not working with custom control buttons as expected in iOS

I am trying to play and pause the video using custom button. But its not working as expected. The actions are not performed instantly. Even it continue to play after pausing the video.

My code is given below.

        self.playerViewController.kPlayer.play()
        self.playerViewController.kPlayer.pause()

another approach

self.playerViewController.kPlayer.pause()
self.playerViewController.kPlayer.play()