Z depth pass is distorted in Nuke, best way to render it correctly?

Im using unreal engine on a college project for rendering, and doing the compositing and postprocessing inside Nuke, but im having some issues with some of the render passes, for some reason the z depth pass looks stretched in Nuke and cant work with it. Does anyone know the optimal configuration to avoid this or the reason this might be happening? Im new to unreal.