I'm experiencing the exact same issue. I think this actually is bugged. Everytime I fly past the spine on the second attacking phase I can't target any of the weakpoints. They are all "Out of Line Of Site", even though they are right there in front of me. Would love a fix to this. EDIT: In the meantime, anyone having trouble with this can add me as a friend and we can try doing it together. Maybe that will work?