if i understand correctly, the reason is that the following two ford nodes cut off the way and the part of the way between them is removed from the graph.
We are working on a more generic solution where we store properties like street type or ford etc in the graph, which will 1) allow a change in the routing calculation per request (if CH is disabled) and 2) gives this information to the client via more PathDetails so if you route through fords you can notify your users