shouldChangeCharactersInChange is not called when entering text from appleTV remote app

Hi guys,

My app is developed for tvOS. I use shouldChangeCharactersInChange delegate to prevent users from entering more than 8 characters in a textfield. But shouldChangeCharactersInChange is called only when I use the physical Siri remote to enter text. If I use the appleTV remote app on iPhone to enter text, the delegate is not called.
Does anyone have solution in this case?. Thank you