Hi, I am assuming you are using the OSM front page map to test the routing:- https://www.openstreetmap.org/directions#map=16/52.15574/0.56439&layers=N.  Please first refresh/reload that webpage in your browser. Now paste in the postcodes. For me the three car routing options work as expected going via Malting End. I must admit there is one problem, when reversed the GrapHopper option is incorrect. This points to the GrapHopper either not using up-to-date data or not using the OSM data correctly.

I've now added locked=yes to the gate.

You should now find the same routing as I do. But bear in mind that the delivery problem might still be that Amazon uses the OSM map data incorrectly, disregarding access restrictions in the map data..

Regards Bernard.