  It was argued that the Raychaudhuri equation with a quantum correction term
seems to avoid the Big Bang singularity and to characterize an everlasting
Universe [PLB741,276(2015)]. Critical comments on both conclusions and on the
correctness of the key expressions of this work were discussed in literature
[MPLA31(2016)1650044]. In the present work, we have analyzed the perturbative
(in)stability conditions in the inflationary era of the early Universe. We
conclude that both unstable and stable modes are incompatible with the
corresponding ones obtained in the standard FLRW Universe. We have shown that
unstable modes do exist at small (an)isotropic perturbation and for different
equations of state. Inequalities for both unstable and stable solutions with
the standard FLRW space were derived. They reveal that in the FLRW flat
Universe both perturbative instability and stability are likely. While negative
stability modes have been obtained for radiation- and matter-dominated eras,
merely, instability modes exist in case of a finite cosmological constant and
also if the vacuum energy dominates the cosmic background geometry.
