The peak fairly appears now.
Well, I’m afraid this has definitely to be well understood, since one has to know which quantity (s)he’s actually plotting. Obviously dN/dE (which is the FLUKA result, i.e. Y) by definition is not the same as EdN/dE (which is dN/dlog(E)). The plotting selection is dictated by the adopted energy scale/binning on the X axis: if the latter is linear, on the vertical axis it should be dN/dE (Y); if it is logarithmic instead, it should be dN/dlog(E) (<X> * Y). You may want to carefully look at the training slides (7-12).