Hi Popsaka,
this is where someone like Househobbit could really help. He is a guru on missions.
Where the _mission.xml file says " Type="mission_target_facility" Spawns="railtraffic.spawns" " , that tells you that the dummy spawning facility controls the distance at which the rail traffic spawns.
I am guessing that if that distance is relatively short, the trains might not at first be moving when you appear on the scene.
To test this, you could open the mission_target_facility in the Facilities folder, and edit the distance at which spawning events occur. I don't have the stuff in front of me but the number will be something like 8000, which is presumably the distance you are away from the facility when the rail traffic spawns. So you could try editing the distance to something a bit larger, and fly the same qc mission again.
By the way, are you warping in toward the target? That might alter the behaviour of spawned vehicles, not give them enough time to start moving.
In campaign missions, when I fly CAS or search_destroy against armored ground formations, I find that the tanks all sit stationary when I view them by selecting the target and cycling thorugh F4. That is, I am seeing them at a great distance using the target-player view and the vehicle formation only starts to move when I get to some closer distance. Its a bit of an immersion-killer but then I am looking at the target at a distance where they are impossible to see with the naked eye....
Let us know how your test goes,
D
PS interesting that you are flying in July 1943 in MAW. Have you seen my mod for MAW, changing a lot of entered service dates for xdp files? In stock MAW, flying in 1943 can get problematic as it was never modified (as was intended) to handle missions post 1942. There are problems in campaigns at least, where it is hard to get the complement of fighters and bombers to populate a campaign post 1943 (let alone some of the vehicles to populate ground formations that are part and parcel of the stock spawns used by the game engine for campaign play)....The challenge being to get entered service and left service dates changed to allow the post January 1943 world to work in MAW.