Hi Anis, also if your curves do not meet each other smoothly at the pole area where they touch, that not help make things smooth. It looks like you have some end tangents of the curves not aligned to each other like this:






You want to have curves meet up in a shared tangent, which means having the end and first inside control points of each curve all on the same line.

Otherwise it means your curves are already starting out not smooth to one another.

- Michael