Bending splines can break the mesh

[_Aka_]

Thanks for posting a followup to help others.

I believe that by setting the orientation of the spline's control points, the problem will be solved, but since you don't need said orientation in your use-case, setting the Orientation mode to None is the easiest fix.

Feel free to ask if you have other questions.
If and when you feel like it, please leave a review for the asset, that helps a lot.
Have a nice day