Trying to create a 2D Surface mesh using 2D Splines

I'm trying to generate a 2D mesh using 2D splines, but I get the following output:

I use the following code

        splines->AddSpline(sp1, 0, sp1.size());
	splines->AddSpline(sp2, 0, sp2.size());
	splines->AddSpline(sp3, 0, sp3.size());
	splines->AddSpline(sp4, 0, sp4.size());
	splines->AddSpline(sp5, 0, sp5.size());
	splines->AddSpline(sp6, 0, sp6.size());
	splines->AddSpline(sp7, 0, sp7.size());

    meshkernelapi::CurvilinearParameters curvilinearParameters;
    meshkernelapi::SplinesToCurvilinearParameters splinesToCurvilinearParameters;

    splinesToCurvilinearParameters.aspect_ratio = 0.1;
    splinesToCurvilinearParameters.aspect_ratio_grow_factor = 1.1;
    splinesToCurvilinearParameters.average_width = 10000.0;
    splinesToCurvilinearParameters.nodes_on_top_of_each_other_tolerance = 1e-4;
    splinesToCurvilinearParameters.min_cosine_crossing_angles = 0.95;
    splinesToCurvilinearParameters.check_front_collisions = false;
    splinesToCurvilinearParameters.curvature_adapted_grid_spacing = true;
    splinesToCurvilinearParameters.remove_skinny_triangles = 0;
    curvilinearParameters.m_refinement = 20;
    curvilinearParameters.n_refinement = 40;

    // create the algorithm
    meshkernel::CurvilinearGridFromSplines curvilinearGridFromSplines(splines, curvilinearParameters, splinesToCurvilinearParameters);

    // compute
    const auto curviGrid = curvilinearGridFromSplines.Compute();

	meshkernel::Mesh2D mesh(curviGrid.m_edges, curviGrid.m_nodes, meshkernel::Projection::cartesian);

	points_voronoi = vtkSmartPointer<vtkPoints>::New();

	for (auto& v : mesh.m_nodes)
	{
		points_mesh.push_back({ v.x, v.y });


	}
	for (int i = 0; i < mesh.m_facesNodes.size(); i++)
	{
		for (int j = 0; j < 4; j++)
		{
			indices_mesh.push_back(mesh.m_facesNodes[i][j]);
		}
	}

and the Splines are attached here:
L1.txt
L2.txt
L3.txt
L4.txt
L5.txt
L6.txt
L7.txt
L8.txt

Start with meshkernel::CurvilinearGridFromSplines and its Compute() call, using the attached L1.txt through L8.txt spline inputs and the parameters shown in the issue. Reproduce the generated mesh and compare it with the intended 2D surface, then establish the expected output and identify whether the problem is in the spline inputs, parameters, or mesh conversion.