Big problem on chunk generation (Unity Tilemaps)

Why does this chunk generator, although it works virtually (in the sense that it generates chunks correctly, as seen in the gizmo img#0/img#1 visualization), generate these strange patterns in the tilemap?

img#0

img#1

The code for chunk generation here:

         Dictionary<Vector2Int, Chunk> chunks = new Dictionary<Vector2Int, Chunk>(32);
         public IEnumerator UpdateMap()
         {
             while(true)
             {
                 var cellSize = grid.cellSize;
                 var ppos = playerObj.transform.position;
                 ppos.x = ppos.x / (chunkSize.x * cellSize.x);
                 ppos.y = ppos.y / (chunkSize.y * cellSize.y);
                 var player = new Vector2Int(Mathf.RoundToInt(ppos.x), Mathf.RoundToInt(ppos.y));
                 Debug.Log(player);
                 string chunkReg = "*CHUNKS*";
                 for (int x = player.x - chunkArea.x; x <= player.x + chunkArea.x; x++)
                     for (int y = player.y - chunkArea.y; y <= player.y + chunkArea.y; y++)
                     {
                         var pos = new Vector2Int(x, y);
                         if (!mapBounds.Contains(pos) || chunks.ContainsKey(pos))
                             continue;
 
                         chunkReg += $"\n {pos}";
 
                         //var chunk = new Chunk(pos.x * chunkSize.x, pos.y * chunkSize.y, chunkSize.x, chunkSize.y);
                         var chunk = new Chunk(pos.x, pos.y, 1, 1);
                         chunk.Generate();
                         chunk.Draw();
 
                         chunks[pos] = chunk;
 
                         qtree.Insert(new Point(pos, chunk));
 
                         yield return null;
                     }
                 chunkReg += "\n END";
                 Debug.Log(chunkReg);
                 yield return null;
             }
         }

The code for the current chunk filling in tilemap:

         public void SetBlock(RectInt bounds, TileBase tile)
         {
             int xPos = bounds.x;
             int yPos = bounds.y;
             int w = xPos + bounds.width;
             int h = yPos + bounds.height;
 
             for (int x = xPos; x < w; x++)
                 for (int y = xPos; y < h; y++)
                 {
                     map.SetTile(new Vector3Int(x, y, 0), tile);
                 }
         }
         public void DrawChunk(Vector2Int position, bool draw)
         {
             var t = draw ? tile : null;
             //SetBlock(new RectInt(position.x * chunkSize.x, position.y * chunkSize.y, chunkSize.x, chunkSize.y), t);
             SetBlock(new RectInt(position.x * chunkSize.x, position.y * chunkSize.y, chunkSize.x, chunkSize.y), t);
         }

This problem doesn't seem to make any sense to me, do you understand? So ... if anyone knows any way to help me with this, I will be very grateful