The suppression factor for single inclusive jets in Pb+Pb collisions at the Large Hadron Collider (LHC) has a weak dependence on the transverse momentum pT and remains almost the same at two colliding energies, √ s = 2.76 and 5.02 TeV, though the central rapidity density of bulk hadrons increases by about 20%. This phenomenon is investigated within the Linear Boltzmann Transport (LBT) model, which includes elastic and inelastic processes based on perturbative QCD for both jet shower and recoil medium partons as they propagate through a quark-gluon plasma (QGP). With the dynamic evolution of the QGP given by the 3+1D CLVisc hydrodynamic model with event-byevent fully fluctuating initial conditions, single inclusive jet suppression in Pb+Pb collisions from LBT agrees well with experimental data. The weak √ s and pT -dependence of the jet suppression factor at LHC are found to result directly from the √ s-dependence of the initial jet pT spectra and slow pT -dependence of the jet energy loss. Contributions from jet-induced medium response, influence of radial expansion, both of which depend on jet-cone size, and jet flavor composition all conjoin to give a slow pT -dependence of jet energy loss and the single jet suppression factor RAA, their dependence on √ s and jet-cone size. Single inclusive jet suppression at √ s = 200 GeV is also predicted that actually decreases slightly with pT in the pT < 50 GeV/c range because of the steeper initial jet spectra though the pT -dependence of the jet energy loss is weaker than that at LHC.