Javascript – Unable to get total number of elements in Playwright

I implemented a Page Object Design pattern to my automation suite and for a simple test case, I’m trying to get total number for elements from a simple table in https://www.saucedemo.com/inventory.html website. But unfortunately im getting

 Error: locator.waitFor: Target closed
    =========================== logs ===========================
    waiting for locator('xpath=//div[@class="inventory_item"]') to be visible
    ============================================================

       at ../pages/InventoryPage.ts:19

      17 |
      18 | async selectRandomItem(){
    > 19 |   await this.colTable.waitFor({state: "visible"}); //issue is here
         |                       ^
      20 |   const itemCount = await this.colTable.count();
      21 |   return await itemCount;
      22 | }

This is my inventory.spec.ts file

import { test, expect } from '@playwright/test';
import { LoginPage } from '../pages/LoginPage';
import { InventoryPage } from '../pages/InventoryPage';

test.describe("Inventory Page Tests", () => {

  let loginPage: LoginPage;
  let inventoryPage: InventoryPage;



  test.beforeEach(({ page }) => {
    loginPage = new LoginPage(page);
    inventoryPage = new InventoryPage(page);
  });



  test("TC-003: Checking whether random item can be addded to the cart", async ({ page }) => {
    await test.step("1.Log in to the site", async () => {
      await loginPage.visit();
    });
    await test.step("2.Enter correct username and password", async () => {
      await loginPage.login("standard_user", "secret_sauce");
    });
    await test.step("3.Get the number of elements", async () => {
      await console.log(inventoryPage.selectRandomItem());
    });
  });
});

This is my InventoryPage.ts file

import { Locator, Page } from "@playwright/test";

export class InventoryPage {

  readonly page: Page;
  readonly lblLoggedIn: Locator;
  readonly colTable: Locator;
 

  
  constructor(page: Page){
    this.page = page;

    this.lblLoggedIn = page.getByText('Products');
    this.colTable = page.locator('//div[@class="inventory_item"]'); //This is the common element
}

async selectRandomItem(){
  await this.colTable.waitFor({state: "visible"}); //issue is here
  const itemCount = await this.colTable.count();
  return await itemCount;
}
   
   
}

How to fix this issue? This is the table im trying to get total elements