Your screen is really not chroma green. The hue is 95-100 so it is right on the border of being yellow. For sRGB, a chroma green screen should be between 120-140 for the hue. The image you posted extracted fine for me. However, base on your composite, only the other 2 images had issues anyway. I don’t know for sure if the screen color is due to a white balancing being not quite right or if the screen color itself is just not right. In any case, the screen is too yellowish. If the screen color is not due to a white balancing issue then I would consider getting a different screen. the westcott X-drop is my recommendation. It has a true chroma green color and is also wrinkle free. I you are using the x-drop already in that photo (kind of looks like it may be), then there must be a white balancing issue in the camera or post processing causing the hue to be way to low and the image to be too yellowish on the screen color.