I plot a route which includes a waypoint of Ouistreham "Brittany Ferries route to Portsmouth" I add Brittany ferries Portsmouth as the next waypoint and it routes me via the channel tunnel.
When I add this two in the address fields (see picture) I get the ferry. Do you type in something else?
Yes I type Brittany Ferries portsmouth and Brittany Ferries Ousitreham, however when I try using your entries it takes me through the Chunnel. Other combinations route me through the Cherbourg ferry.