Wim??
RIGHT, completely correct.

I also had this happen in the cloth room.

When you render at crease angle 180° and Smooting ON, and have a thight fitting clothing fitted, that fits perfectly close to the figure in preview?

Well, at render time the figure comes poking through because of the calculated Smoothing can round out the figure mesh into the clothing.

I even send an example of this happning to SM.

Smoothing rounds out sharp corners.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!