Camera Rail. Dooh is that complicated!

Just trying to do a simple camera drive with a rail:

Cinematic How To's | Unreal Engine DocumentationCameraRigRail/

Drag a camera and rail to scene.
Attach camera to rail.
Edit rail points (you can’t simply click a point and then drag while holding)
then again add both to sequencer (why both, when I already have attached the camera?)
Add a cut track.
Add the cinema camera to the cut track.
Add a key on the transform channel of the camera actor.
Add a “Current Position on Rail” track to the rail.
Goto sequence end.
Set the rail control in the details panel to 1.
Don’t forget to add another key to the transform track of the actor.
Select the cine camera actor, then check enable ‘Look at Tracking’
Set your camera target using the field ‘Actor to track’.
Lock the viewport to the cut track (the camera icon on this track?)
Click the preview play button.

Result:
The camera doesn’t move, at least not for me.

I think the process described above is not intuitive.
There is absolutely no chance to find out the needed steps without following
a documentation - and even then…