  Time series measurements in 2H-NbS$_2$ crystal had unravelled a drive induced
transition wherein the critical current (Ic) changes from a low to a high Ic
jammed vortex state, via a negative differential resistance (NDR) transition.
Here, using multiple current (I) - voltage (V) measurement cycles, we explore
the statistical nature of observing the NDR transition in the free-flux-flow
(FF) regime in a single crystal of 2H-NbS$_2$. The probability of observing the
NDR transition always remains finite for a vortex state created with either
fast or slow rate of magnetic field. The probability of observing the NDR
transition in the FF regime is found to systematically increase with magnetic
field (B) in weak collective pinning regime. In the strong pinning regime, the
said probability becomes B-independent. We show that the higher Ic state is
unique and cannot be accessed via any conventional route. While the I-V curves
do not distinguish between zero field cooled (ZFC) and field cooled (FC) modes
of preparing the vortex state, the probability for observing an NDR transition
has different B-dependences for the vortex matter prepared in the ZFC and FC
modes. We find that the NDR occurs in a high dissipation regime, where the flow
resistivity is well above the theoretical value expected in the FF regime. We
understand our results on the basis of a rapid drop in vortex viscosity at high
drives in 2H-NbS$_2$, which triggers a rapid increase in the vortex velocity
and reorganization in the moving vortex matter leading to a dynamical unstable
vortex flow. This dynamical instability leads to the NDR transition into a high
entropy vortex state with high Ic.
