Is K4 installed to a Poser runtime, or did you install it to a DAZ runtime?

I have had this same kind of problem when I used K4 (especially with the Chibi morphs) from a DAZ runtime for rigging.

It went away when I installed K4 directly into the Poser runtime instead.

When you modeled, did you zero the K4 figure and export an obj to use as a mannequin?

When you load K4 in poser, did you zero the figure?  If not, did you try selecting the shirt>body and zero the figure after you conformed?