When you take a blueprint with a train in it and rotate it by 90 degrees twice, the preview for the cargo wagon placement is wrong.
[2.0.11] Cargo wagon preview is wrong after rotation (train/blueprint)
Re: [2.0.11] Cargo Wagon rotation preview is wrong
This seems to be fixed in 2.0.19.
My mods: Multiple Unit Train Control, Smart Artillery Wagons
Maintainer of Vehicle Wagon 2, Cargo Ships, Honk
Maintainer of Vehicle Wagon 2, Cargo Ships, Honk