ERROR: "Explicitly marking highway type service road to allow correct routing".
Oude Leusderweg is AND throughroute (bicycle, foot: highway=track) AND access to campsites (vehicle, foot: highway=service) AND hiking route "Natuurpad De Korte Duinen" (foot: highway=track).
Therefore (highway=service) is error.
Routing is correct for both highway=service and highway=track.
Revert to history: (set highway=track) + (set tracktype=grade2).