Most left and right slides jump way to either side

I use nothing but the standard settings: a concave, continous carousel through about nine images. But the most left and right slides jump way out of my layout.

See scatch:

I have also tried to insert just the demo with the same settings, but the same happens.

Is there a way to influence this?

Thank you very much for help.

Start with the Bee3D demo and reproduce the issue using a concave, continuous carousel with about nine images and the standard settings. Compare the leftmost and rightmost slides with the attached screenshot; done means both remain within the intended layout instead of jumping outward.

Written by the indexing model from the issue text.