I have a feeling that it takes mirror as a absalute -100 scale in all axis this is why the deformation looks like that. while we are trying to do a mirror scale of -100 on x axis… I havnt found a solution to fix it . even if I manualy scale it it wont work. so I have centred it to the scene and rescaled it in unreal. but the section that I am having the issue with is rather small so wasn’t a problem to fix it