Greenscreen not working proparly in Zoom

Hi, I have a problem. Today I installed a Green Screen in order to get a better and more professional outlook. 

But..... When I tick the box: "I have a Green Screen"  it's not looking good. If I use it without ticking the box, it looks a little better but I have no advantage of my green screen... The first one is with I have a Greenscreen, the second without... Can you help me? 

Cheers Dries