[BUG] Assertions took very long in headless mode

Context:

• Playwright Version: 1.21.1
• Operating System: Linux 5.13 Ubuntu 20.04.4 LTS (Focal Fossa)
• Browser: WebKit …devices[“iPhone 12”]

System:

• Memory: 6.38 GB / 11.53 GB
• Container: Yes

Binaries:

• Node: 14.18.3 - /usr/local/bin/node
• npm: 8.1.4 - /usr/local/bin/npm

Languages:

• Bash: 5.0.17 - /usr/bin/bash

Repo Link

Code Snippet

import { test, expect } from "@playwright/test";

test("test checkboxes and Radio buttons without placements", async ({ page }) => {
  const newSignUrl = "https://staging.scrive.com/s/9221714692412077704/9221932570715111975/e2d6e750aba8283a";

  await page.goto(newSignUrl, { waitUntil: "networkidle" });
  await expect(page).toHaveURL(/new\/sign/);
});

Describe the bug

It took extra long time to pass the test in headless mode. The test report video is very confusing, look like UI is shaking all the time.

Comparison

For headed mode assertion timeout is 5s without any issue. For headless mode assertion timeout it has to change to at least 10s for test to pass.

[yury-s]

I cannot reproduce it on Ubuntu (neither in docker nor on a native hardware).

@hex0cter @loxinchi could you please check if it is still reproducible with playwright 1.23.2 ?

[pavelfeldman]

I can reproduce it, only in headless mode, the viewport is shaking.