Solution routing loop exists before completing all stops

[nimishdesai1989]

I am using google OR tools CVRP to find the optimal solution for vehicle routing. Lets say I have 4 stops to cover, the solution sometimes randomly exits at a loop where below program line returns an index value higher than expected to exit the loop.

index = solution.Value(routing.NextVar(index))

so if the expected index is 2 for e.g it returns 3 and solution exits.

but if the same dataset is used again after sometime, the solution works well. this issue happens intermittently but it is still impacting the overall app. Has anyone had this kind of issue and are there any ideas to solve this ?