How do you assign custom materials to your custom mesh?

I have a script to create a custom mesh, a custom material using LWRP's shader graph. Decided to put them together but it doesn't seem to work. The cube and the quad next to it looks just fine tho.

Here's a peak using System.Collections; using System.Collections.Generic; using UnityEngine;

 [RequireComponent(typeof(MeshFilter))]
 [RequireComponent(typeof(MeshRenderer))]
 [ExecuteInEditMode]
 public class MeshEditor : MonoBehaviour
 {
     public Material material;
 
     List<Transform> verticesTransforms; //three of these transforms so that i can change vertices (per triangle) easily
 
     Mesh mesh;
 
     List<Vector3> curr_vertex;  //modify vertices 3 at a time, then add them to the vertices list later
     Vector3Int curr_triangle;  //modify the current triangle then assign to the list later
 
     public List<Vector3> vertices;
     public List<int> triangles;
 
 //-------------------------------------------------------------------------------------------------------------
 
     void Start()
     {
         if (!Application.isPlaying)
         {
             mesh = new Mesh();
         }
     }
 //-------------------------------------------------------------------------------------------------------------
 
     void Update()
     {
         if (!Application.isPlaying) //Just need this only to help be build things
         {
             GetComponent<MeshRenderer>().material = material;
             GetComponent<MeshFilter>().mesh = mesh;
 
 //-------------------------------------------------------------------------------------------------------------
             while (verticesTransforms.Count < 3)
             {
                 verticesTransforms.Add(null);
             }
             while (verticesTransforms.Count > 3)
             {
                 verticesTransforms.RemoveAt(verticesTransforms.Count - 1);
             }
             while (curr_vertex.Count < 3)
             {
                 curr_vertex.Add(Vector3.zero);
             }
             while (curr_vertex.Count > 3)
             {
                 curr_vertex.RemoveAt(curr_vertex.Count - 1);
             }
 //-------------------------------------------------------------------------------------------------------------
 
 
             for (int i = 0; i < 3; i++)
             {
                 if (i < 3)
                 {
                     if (verticesTransforms[i] != null)
                     {
                         verticesTransforms[i].parent = transform; //nice and organized
                         curr_vertex[i] = verticesTransforms[i].localPosition; //adjust the vertex by moving the transforms in the editor
                     }
                     else
                     {
                         verticesTransforms[i] = new GameObject("Vertex Transform").transform; //in case the vertex is missing
                     }
                 }
 
                 vertices[vertices.Count - 1 - i] = curr_vertex[i]; //now add the recently-modified current vertex to the list
 //-------------------------------------------------------------------------------------------------------------
 
                 if (i == 0)
                 {
                     triangles[triangles.Count - 1] = curr_triangle.x;
                 }
                 if (i == 1)
                 {
                     triangles[triangles.Count - 2] = curr_triangle.x;
                 }
                 if (i == 2)
                 {
                     triangles[triangles.Count - 1] = curr_triangle.x;
                 }
 
                 //used vector3 for triangle cuz it's a bit more convenient (for me)
             }
 
 //-------------------------------------------------------------------------------------------------------------
 
             mesh.triangles = triangles.ToArray();
             mesh.vertices = vertices.ToArray();
             mesh.RecalculateNormals();
             mesh.name = "custom mesh";
         }
     }
 }