Dialog window visible when running headless

[klappradla]

Hi 👋

First off, thanks for the really awesome work you're doing here 🙇! Really appreciating it 💜

Setup

We just recently moved the test suite or a larger legacy app from Selenium to Cuprite. We are using RSpec feature tests with Capybara running a headless Cuprite driver with these options by default:

Capybara::Cuprite::Driver.new(
  app,
  window_size: [1280, 1024],
  browser_options: {
    'disable-dev-shm-usage' => nil,
    'disable-search-engine-choice-screen' => nil,
    'disable-backgrounding-occluded-windows' => nil,
    'disable-renderer-backgrounding' => nil,
    'disable-background-timer-throttling' => nil
  },
  headless: true,
  process_timeout: 30,
  timeout: 30
)

Within our tests, we have multiple occasions, where we accept a confirmation dialog like so:

accept_confirm { click_on 'Destroy' }

Problem

Even though the tests are running in a headless browser, we see the dialogs flashing "visible" when we run the tests. I hope the screencast can capture the scenario:

confirmflicker.mp4

Expected

Our expectation would have been, that everything stays hidden when we run headless. Or is there something we are missing in our setup?