2 Point Arc does not close geometry when spanned across 3 dimensions

Dear community,

I am trying to close a plane that spans across 3 dimensions with a 2 point arc.
But when I finish the arc, the plane does not close (3rd geometry from left in sample .skp).
In a two dimensional space, the 2 point arc closes (First geometry from left in sample .skp)
What am I doing wrong or rather: How can it be done?
Bildschirmfoto 2024-03-28 um 09.55.18

GeoArcs.skp (134.7 KB)

Thank you!

Sketchup is a face modeller, so all surfaces are created by flat faces, a triangle will always form a face. So for your 3d curve to form a surface you need to stitch it. Then smooth it.
I have done that here by joining the vertices, then smoothing with the eraser and ctrl.
GIF 28-03-2024 8-15-09 PM

Awesome! That helped me A LOT!
Of course, I was not expecting this:

But I guess, that is something that I have to live with, right? Or can I somehow “paint” the entire smoothed plane with a texture without having each segment texturized on its own?

Seems to be a bug in the web version, you can make it work in pro.
GIF 28-03-2024 9-54-21 PM