Virtual Keyboard can not be closed!?

I have a strange problem with entering a text in a text field using a virtual keyboard on devices:

Players can enter a URL to download an external game level, but when the virtual keyboard is shown I can see a small keyboard button on an iPad which can close the virtual keyboard BUT on an iPhoneX this keyboard button is missing and clicking RETURN for example is NOT closing the keyboard. So the keyboard is open all the time and exactly hiding the button on screen which will start the game level. So the player get stuck because he has no option to close the keyboard.

Is there a way to show a keyboard close button on iPhoneX virtual keyboards also? How do you handle this problem?

Daniela

I use a down arrow button sprite image. And when people touch it I call:

native.setKeyboardFocus( nil ) 

Thank you very much for the tip!