Grrrrrr! I made the adjustments to the shadow catcher parameters and it STILL came out wonky, and when you look at the image, you can see a definite line going across the middle through her waist as well. I'm beginning to think this particular HDRI file is bad because I've done well with the others I've used, some from PolyHaven and others from different sources. Throwing in the towel, I think :'(