GenX Odd Pinching

MacSavers

I've been converting some new V4 characters that I just bought on sale and when comparing them from some renderings, I have started to notice that some of them have some odd pinching near the underarm on the frontside of the body. I do have the model posed in a standard walking pose for model to model comparison.

I've included an image showing the problem On the left is Exnem's Jonesy as is the closup in the middle. On the right is Qgirl showing a more pronounced pinching.

Is there anything I'm doing wrong that's causing this? Is there a fix I can do on my end to correct this?