Firefox does not open in headless mode with headless option

[ctrl-alt-deliberate]

The following code will open a Firefox window instead of executing in the background.

import asyncio
from selenium_async import use_browser, Options

async def browse():
    async with use_browser(options=Options(headless=True)) as driver:
        driver.get('https://google.com')

asyncio.run(browse())

In fact, headless=True is the default, but a window will open by default as well.
See link for headless mode changes.