Why is there compatibility issue between the Toshiba C11/F7C and LG DTP/C3F Screen for iPhone 7 Plus & 8 Plus? 
In short, as you can tell from their names, they are produced by two different companies, Toshiba and LG. Therefore, even though the screens are made to Apple’s strict specifications, compatibility issues still exist and if you cross install screens between these two different manufacturers (Install Toshiba screen on a device that was originally fitted with LG screen or vice versa), there is a very high chance that you will experience screen touch issues. 

Three ways to distinguish screens from different manufacturers: 

1. Serial Number on 3D Touch Panel
If you are to take a look at the touch panel of the screen, the first three letters will identify the manufacturer, a