Huwdiprose
I've checked this on Graphhopper too and can reproduce what Steve Rice found.

However I can get this error to appear when using Maps.me.

The road was previously an unclassified minor road, which seems incorrect anyway. I've amended here: https://www.openstreetmap.org/changeset/89485771#map=19/51.90999/-0.46617&layers=N

Will test in Maps.me next time there's an update.