Input Text does not work fine in iFrame when I use iOS

Hi,
I'm creating an hybrid App for iOS and Android in which there is a main index page who contains an iframe in which appear the pages of my website (mobile version). If I use an iOS device, when I'm compiling the input text of login page, if I touch the diasplay out from the input text and then I try to write, it does not work anymore; I must select another input text, and then return to the previous. On Android there is no such issue. Also, if I use the same iFrame on Safari browser of iPhone/iPad, everything works fine and there are no problems with keyboard.
Can you resolve this problem or help me?