playwright: [BUG] "TypeError: Cannot read properties of undefined (reading 'childFrames')" when running tests in Firefox

Context:

• Playwright Version: 1.28.0-alpha-oct-28-2022
• Operating System: Mac (M1 Pro)
• Node.js version: v16.16.0
• Browser: Firefox
• Extra:

Code Snippet

import { test } from '@playwright/test';

test('test', async ({ page }) => {
  await page.goto(
    'https://id2.navexglobal.com/SecureTokenServer/Auth/SamlLogin?SAMLRequest=jZJfa9swFMW%2FitF7LFsLaSbiQNpQFsg2t3b7sJciy9eJmCy5ulL%2FfPvKzko7xkpBD%2BLq8Lv3nKsVil4PfBP80VzDfQD0yVOvDfLpoSDBGW4FKuRG9IDcS15tvu85SzM%2BOOuttJokG0RwXllzYQ2GHlwF7kFJuLneF%2BTo%2FYCc0tZa1wuTGvEATwdtG6FTaXtaHVXTWA3%2BmCJaOuIZLX9WNUm2cR5lxEh%2B46iW%2FcsAGRzU9jeYsTU4OlqiVTSxtwdlSLLbFuSuW3YLaDNYZPOzufwSTytFEy9z1nXZYhlliAF2Br0wviAsY2yWZzO2rFnG48m%2F%2FiJJ%2Bcf3uTKtMoePQ2pOIuTf6rqcnWzdgsPJUhSQ9WqMmk%2BN3bvwP8aK18TJ%2BvP5rui7Vqe%2BA%2F8R2bttabWSz8lGa%2Ft44UB4KEhOkssR6f8%2FSp7mU0W1s26S8mBwAKk6BS1JqnKkXwWhx4IriAje9tM%2BfVwtKg%2BErk9j%2Ff0L1y8%3D&RelayState=cookie%3A1666988419_8131'
  );
  await page.getByPlaceholder('User name').fill('Martin1');
  await page.getByPlaceholder('Password').fill([PASSWORD]);
  await page.getByRole('button', { name: 'Sign In' }).click();
  await page
    .getByRole('link', { name: 'Policy & Procedure Management' })
    .click();
  await page.locator('id=SideBar_NewDocuments').click();
  const [page1] = await Promise.all([
    page.waitForEvent('popup'),
    page.getByRole('link', { name: 'HTML Document HTML Document' }).click(),
  ]);
  await page1
    .frameLocator('iframe[name="WizardPanelPropertiesEdit_Iframe"]')
    .locator('input[name="ctl00\\$ContentPlaceHolder1\\$TitleField"]')
    .fill('Test');
  await page1
    .frameLocator('iframe[name="WizardPanelPropertiesEdit_Iframe"]')
    .getByRole('button', { name: 'Save' })
    .click();
  await page1.getByRole('cell', { name: 'Reviewers' }).click();
  await page1
    .frameLocator('iframe[name="WizardPanelPropertiesEdit_Iframe"]')
    .frameLocator('#UserFinderFrame')
    .locator('input[type="checkbox"]')
    .check();
  await page1
    .frameLocator('iframe[name="WizardPanelPropertiesEdit_Iframe"]')
    .getByRole('button', { name: 'Save' })
    .click();
  await page1.getByRole('cell', { name: 'Approvers' }).click();
  await page1
    .frameLocator('iframe[name="WizardPanelPropertiesEdit_Iframe"]')
    .frameLocator('#UserFinderFrame')
    .locator('input[type="checkbox"]')
    .check();
  await page1
    .frameLocator('iframe[name="WizardPanelPropertiesEdit_Iframe"]')
    .getByRole('button', { name: 'Save' })
    .click();
});

Describe the bug

NOTICE - The password for this test is missing. Upon request, I can privately message it to whomever will be reviewing this issue. As per the request on this issue and this issue, I am opening a new issue. When running tests in Firefox, I am getting the following error: TypeError: Cannot read properties of undefined (reading 'childFrames')

I tried using next 1.28.0 which purportedly fixed it, but it still seems to be ran issue.