xNormal not producing tangent space nmaps

Hi, I've been trying to take a map out of zBrush in object space and convert it to tangent space in xNormal. It seems to be giving me an object space map from an object space map. 

I'm using the unity plugin but it doesn't work with the default one either. 

Any ideas why?

I have uploaded the images in order: Original object space, xNormal export of supposed tangent space, and tangent space direct from zbrush. 

 Thanks!