Why is character mesh wrinkled when rubber cloth preset sim is applied?

I have character mesh where I applied rubber cloth preset sim (to achieve soft body) with specified pin group, self collision enabled, collision collection and disabled gravity. When I run animation for unknown reason part that should be still and wait for self collision (by hand) is wrinkly. My aim is to be able to squash boob by hand (fingers). When I tried it on primitive objects like cube or ico sphere, it’s not happening. What am I doing wrong?
here is the picture:

And my blend file (from googel drive as I am new member and can’t upload files):