Hi everyone, does anyone know why this keeps happening on random vertices along the spline?

The only thing that seems to solve it is when I fillet the vertex, but I'm wondering if there's a simpler solution, rather than going through each and every vertex, and filleting the ones that are buggy.

3dsmax 2021

The only thing that seems to solve it is when I fillet the vertex, but I'm wondering if there's a simpler solution, rather than going through each and every vertex, and filleting the ones that are buggy.

3dsmax 2021