Hello friend, luckily, I am an iPhone technician, it is very typical that this happens especially on the iPhone 6 ... if you dare and want to repair it, it is possible that they bring an antenna behind the plate that is changed very easily the most complicated is to disassemble the complete equipment and remember the position of the screws if you think you are capable of doing everything carefully you can do it with a very low cost .... if you want more advice answer me and I help you without problem.