Specific alternative route requests leads to IllegalStateException

[karussell]

With master, CH enabled and the following request:

{
  "points": [
    [      13.38886,      52.51703    ],
    [      13.05914,      52.400931    ]
  ],
  "profile": "car",
  "alternative_route.max_paths": 3,
  "algorithm": "alternative_route"
}

I got an exception (seems to be very rare):

[dw-2492 - POST /route?] ERROR i.d.j.e.IllegalStateExceptionMapper - Error handling a request: 649e985b5c09e7a7
java.lang.IllegalStateException: waypoints are not included in points, or waypoint indices are wrong
	at com.graphhopper.util.PathMerger.doWork(PathMerger.java:166)
	at com.graphhopper.routing.Router.routeAlt(Router.java:260)
	at com.graphhopper.routing.Router.route(Router.java:116)
	at com.graphhopper.GraphHopper.route(GraphHopper.java:1254)
	at com.graphhopper.resources.RouteResource.doPost(RouteResource.java:180)

(different points, or profile or max_paths count did not trigger this)

Update: Another request fails with the same error but no alternative route involved and even CH can be disabled and the error still occurs:

{
  "points": [
    [      2.47736588295,      44.4494394989    ],
    [      2.477205,      44.449389    ]
  ],
  "profile": "foot"
}

[hendrik-r]

I was unable to reproduce this bug with the default configuration and https://download.geofabrik.de/europe/germany-latest.osm.pbf as the map bounds.
Would you mind giving me some pointers that would help me to reproduce it?

[karussell]

Likely the problem is that this happens only for larger areas. Maybe something related the CH preparation. We got both errors (with or without alternatives) with the planet pbf only (cannot reproduce locally atm).

[easbar]

I was able to reproduce the second request in the initial comment both locally and online. But I could not reproduce the first one.