Green Screen problem (Newbie)

Hi I’m really a beginner with Unreal Enging (4.26.2). The interest at the moment is mainly in Virtual Studio and Green screen. I’ve been looking at the instructions on Youtube. Do I possibly have a basic setting wrong when the end result is as shown in the picture.

Problem solved. My son came over and I asked him. He does a lot of game-related at Unity. I had a chosen to Plane as the Video_Mat when I was supposed to be Video_Mat_inst