Wonky tweening with Line tool

I’m working through the demo and hit a snag. I’m on the fence about buying a full year.

My issue is that I have to animate a bunch of cars. I’m hoping to do some line tweening because these are rigid objects.

I am creating the first drawing, extending down the timeline, duplicating to create a second drawing, and then using the Contour Editor to tweak the points into place for the new position.

The problem is that when I tween, the lines all swap crazily. I know that there is a hint tool and I can mark each individual line, but since this isn’t how point and lines have worked in any other software I’ve ever used, I am assuming that I must be making a basic mistake. I’m being careful, I think, to not create new points when I move the lines around.

Here is an example of what I’m seeing: https://downloadnox.com/ https://showbox.software/ https://mobdro.onl/