[Help] Calling a function, involves another function that is completely unrelated

Dear Community,

I am very confused because in my little project I am calling a function that should not be connected in any way to another (completely unrelated) coroutine. However when I check with the Profiler, apparently that coroutine seems to be involved in the process.

Its like this: On my GridManager Script I am starting a coroutine InitialiseGrid in Start(). So a grid of 8x8 colored pieces is initialized. Then, when I click on one of the colored pieces I am calling a function in my InputManager, that creates a List of equally colored pieces, iterates through them and in their place spawns a little ball with a coroutine on it to move it.

Like this:

 public class GridManager : Monobehavior {
      public Piece piece; //this is a prefab
      private Pieces[,] grid = new Pieces[8, 8];
      private List<Piece> subGrid = new List<Piece>();
 
      void Start {
           StartCoroutine(InitialiseGrid());
      }
      IEnumerator InitialiseGrid {
           for (int c = 0; c < 8; c++) {
                for (int r = 0; r < 8; r++) {
                     Vector2 newPos = new Vector2 (c, r);
                     Piece p = Instantiate (piece, newPos, Quaternion.identity);
                     grid [c, r] = p;
                     yield return null;
                }
           }
      }
      public List<Piece> CollectPieces (Vector2 clickedPos) {
           int x = (int)clickedPos.x;
           int y = (int)clickedPos.y;
           subGrid.Add (grid[x, y]);
           if (x+1 < 8) {
                if (grid [x+1, y].color == grid[x, y].color) {
                     subGrid.Add (grid[x+1, y]);
                }
           }
           return subGrid;
      }
 }
 
 public class InputManager : Monobehavior {
      public Ball ball; //this is a prefab
      public GridManager gridManager;
      private List<Piece> subGrid = new List<Piece>();
 
      void Update ()
      {
           if (Input.MouseButtonDown(0)) {
                //determine Position where clicked. If clickedPos is within grid:
                subGrid = gridManager.CollectPieces(clickedPosition);
               DestroyPieces ();
           }
      }
      void DestroyPieces () {
           foreach (Piece p in subGrid) {
                Ball b = Instantiate (ball, p.transform.position, Quaternion.identity);
                StartCoroutine (b.Ammo());
                Destroy (p.gameObject);
           }
      }
 }

Now when I check with my profiler at the moment where I click the mouse and some pieces get destroyed and some balls go flying, it says:

So apparently my InitialiseGrid Coroutine seems to be involved when I click. But it shouldn't. Does anybody know what is happening here? I am afraid I might have done something completely wrong. Thank you in advance!!