Is it possible you get some screenshots?
Sure, I'll get some tonight!
Ok, editing w/screenies.
Here's a default undie, (I have a texture replacer for tf undies, but you can see the old thumbnail.)

Here's a custom content pair undies, of It has block feet even though though it uses a default mesh.

Here's some pictures of default PJ's and Swimwear that have no problems at all using your meshes.


ONLY the underwear mesh for teen female is broken for me. Everything else works fine and if there are any other default replacement meshes for teen females that could be messing it up, I'm not aware of it.