Hi Anis,

> This is not critical problem. Just curious why ?

It's something in the surface/surface intersector that is sometimes doing things in portions of surfaces.

An exact NURBS sphere is made up of several segments internally with what are called "fully multiple knots" in between each of them. One of the fully multiple knot locations is in that spot that got split up.

In the Jun-23 beta release, there is a new "Merge" command that you can set up on a keyboard shortcut - if you select that object and run Merge on it, it will glue those edge fragments together into a single longer edge.

At some point I will be fixing up the booleans to have those things automatically merged, the only reason I have not added that yet is that I want to try and avoid modifying any edges that may have been split up previous to the boolean.

- Michael