Hiding text input line on Android and iOS touch keyboards.

I am really struggling with this one and I have search for many solutions on this forum on the web and this forum and cant really figure this out.

I am building an app with text input fields for username and password and I cannot for the life of me get rid of the top line on the touch keyboard that previews the text input.

I have ticked the 'Hide Mobile Input' bool on the input fields and even tried injecting "TouchScreenKeyboard.hideInput = true;" at various points in my code and I cannot get rid of it, screenshot of the offending issue attached.

If anyone can shine some light on this it would be most appreciated.