Difference between Shielding and ShieldingLEND during neutron capture

We have a detector with EJ-200 scintillator and a thin LiF:ZnS layer. Cf252 source neutrons are created near the detector. Li6 neutron capture has a particular energy release, 4.78 MeV. Shielding gives the correct results. Though, when we read about the explanation of Shielding and ShieldingLEND on Shielding — PhysicsListGuide 11.1 documentation, ShieldingLEND should be used in our case. Our results are given below:

Why does the ShieldingLEND count higher energy depositions more and totally miss the alpha and triton particle energy peaks in which Shielding correctly simulates?