Chroma key with small screen

SteeveB, your suggestion worked brilliantly. Sandwiching the talent with two backgrounds and Masking off the bad green screen did the trick. I’ve attached a snapshot. Thank you! Shotcut%20chroma%20key

There is still a residual green shadow in the lower center of screen, but it’s within tweakable range.
Your video link [https://streamable.com/1a5xm] was very helpful. Did you make it?