Inconsistent results with same addresses

Hi. Just wondering if this expected behavior. We’re using the graphhopper api to optimize delivery routes. It’s a pretty straightforward implementation - one truck doing all of the stops on the route. We have some routes that are pretty densely packed - the stops might only be a couple minutes from each other. When we get the optimized driving route from graphhopper - using the same set of addresses - the route that is returned is not always consistent. For example, it might put A, B, C in the 1, 2, 3 position on one request and then B, A, C in the second. Is this expected behavior or should the algorithm - if it’s always dealing with the same addresses - always return the same optimized order?

Do you use the /vrp endpoint or /route with optimize=true. I think in both cases the returned order might not be fully deterministic, but not entirely sure. Are the different returned routes very different in terms of traveling time?

According to Graphhopper support, if you’re feeding in the same waypoints you should always get the same result. So I suspect our issue is with the users.

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