Hi Professor! Please note that this is the support thread for UCS. For CC3 support you might want to contact them at their forums.
As a side note, it does seem that the clothes are clipping through the skin – probably related to less than perfect skinning. You might have to re skin those clothes or hide parts of the base character. Another technique that you might use for this, that UCS uses, is to inflate the cloth along the normals. It might help with some clothing. You can “inflate” cloth in the material graph with these nodes:
Kind regards