Deposite energy of the compt process is not continuous

I have simulate the process of gamma and liquid argon. I get the deposited energy by “thestep->GetTotalEnergyDeposite()”. All we should known is that the lost energy of gamma or obtained enrgy of electron is continuos when compton is happened. But in Geant4, when the step is gamma and the process is compt, the deposite energy of this step is discontinuous energy but some special value such as 0.24943keV/0.31343keV… I have tried the G4EmLivermorePhysics, G4EmStandardPhysics and G4EmLowEPPhysics, but I get the same result. So how does these discontinuous energy form and what is the physics?