Hi there! Thanks for the quick reply!
That (entering waypoints manually on the FLPN page via the relevant LSK) is how I was trying to enter the waypoints. I have also tried entering the next waypoint via the page that comes up when you click the previous waypoint (I think the LAT REV page).
BK404 and BK402 don't seem to work. I haven't tried others in the area yet.
Like the user above, these waypoints do work in other aircraft.
W