I have encoutered this problem dozends of times but I don't really know if there is a name for this. The key itself looks ok, but where 2 people are intersecting you get this bright edge that travels along the intersections. (see image)
Not sure which keyer you are using but sometimes Edge Color Correction can help here.
Also I sometimes pre process my green footage in a sub comp. I use Hue Saturation to boost only the green channel saturation and also sometimes add a denoiser. Then in the main comp I pick that now much more saturated green....this helps define the edges better.
I almost always use Edge Color Correction in Keylight and I can make any slightly green or brighter edge areas match the shirt they are wearing or a background color etc to make a more convincing composite.
Tilt Media Inc.
Video Production, Post, Studio Sound Stage