It looks like you tried to extract the image twice. The first time with EZ Green Screen and then again with Image Extract? You can’t do that. Image Extract needs to start with a flattened image so it flattens the transparency against white and then re-extracts.
If you send me the original green screen image then I will test it tomorrow and post the extraction settings. For the floor, you should try the floor removal actions from the “action hacks” downloads. Run this after EZ Green Screen, not the Image Extract plugin. The download for the actions is on this page in the link. Also see the video on the page for the floor removal actions.