The answer is actually that there are two different cameras for the Galaxy S7. One is made by Sony, and the other by Samsung themselves. You need to replace the camera with the correct type of replacement, then it will work.
Here is an article outlining the subtle differences between the cameras:
http://www.androidauthority.com/lg-g6-lg-got-groove-back-757654/
Here is an app you can download to see which camera you have:
https://play.google.com/store/apps/details?id=com.finalwire.aida64