Hello everybody, i’m stuggling to find a solution here and also to find the right headline for my problem, but i hope my following writing will help to understand.
So I have this scene consisting of a room, an actor who speaks to the camera and a big TV Wall behind him playing a video. The scene is made with Lumen lightning and the light in the editor and level sequence looks good. When i render the sequence I notice that, depending on what is shown on the TV screen, the light of the whole scene varies a lot. Sure the video on the screen has brighter and darker parts, which cause a changing of light in the room, but it also lights up the front side of my actor as well as everything behind the TV screen enormously, which appears to be not how light would usually behave. Here is an example of how the light changes during my clip:
Notice the area with the plant behind the sceen and also the actor in the front.
Both, TV screen and actor are jpg sequences placed on planes. It feels like the light coming from the screen is just shining through my actor. How could I avoid this? It also appears that the screen light, also shines to the back to brighten up the room behind the screen. I tried to put a black wall in the same size and position right behind the screen to stop the light spread, but apparently this doesn’t work as expected. Any help would be appreciated 
Thank you in advance.