Lcd shield plate on new display

Hello, try to be as brief as possible. a few months ago the screen of my iPhone broke, after looking for a place to make the change (there are no official stores in my country) they put a screen of very poor quality but functional. 15 days ago that screen broke and I decided to replace it in another place, in this new place they open the iPhone in my face and they show me that the lcd shield plate is not there and they explain to me that it is usually removed since very bad quality screens are not they need it. They also told me that if I got the lcd shield plate they would place it on the new screen. since then my screen of moments works well and of others I can not use since when wanting to type, other letters are activated and not the ones I am touching, for example. they explained to me that this could happen because if the lcd flex is not well positioned it could cause this effect, they replaced several screens several times and although the times in all the lcd varied the fault persisted. Is this possible? Is it only necessary to adjust the LCD shield plate correctly so that the screen works? they also offered to place another screen of lower quality in which worked Perfect except the 3D Touch