Hello, I have the same problem as yours. The proximity sensor is crazy.
During *#0*# test, for the proximity sensor, proximity sensor test displays 1 and screen vibrates constantly and always is green , exactly like you described. I have a samsung S7 Edge.
During calls, the phone screen turns off without holding it to ear! In WhatsApp calls, I can not even hang out because the screen freeze completly!
At first, I thought that it was related to the Roms, I tried a few, and even the Official from Samsung got the same issue.
So with the result from the sensor test, with *#0*#, I am (99%) sure that proximity sensor is guilty, and plan to change it. But how can it have been damaged?? kind of wierd.
How didyou resolved the problem?? did you changed the sensor??
Thx for any feed back, and recommandations.