When the gesture function is triggered, it sends commands through to the app for processing. However, as some apps don't support switching commands, they won't respond to the earbuds' control commands, leading to ineffective gesture control. Rest assured this doesn't indicate any fault with Ear (open).
Please also ensure you're pressing the correct control area on the earbuds. If still unable to trigger the function, try switching to a different music app to see if the function works.