This is strange and still confuse me. I set way points as forward, next up, next right and last is down to hit the colony roof in the middle. But instead of it the missile going up flew to roof and not moving down to hit but just off the map. It's just ignore last way point completely. Plus in few mission, usually with medium USO aliens has a lot of D.P.L.s but they missing too. Not every time of course.
Here the screenshots what I made in debug mode New battle:
But my last way point inside the base. May that's why it not working? It's just ignoring roof wall at all.
P.S.
I did 4th way point just one tile below 3rd on the roof but missile still missing and disappearing
Save file to test. The guy who shoot has 78% on dpl: