Selenium webdriver ignores virtualdisplay under MacOS

[reisenmachtfreude]

I'm running MacOs 15.3.1 with Python 3.9.6 and Quartz. If I execute the following code, the Firefox browser window shows on the normal screen and not in the virtual screen. In general the virtual screen exists as it is listed (ps -ef | grep Xvfb).

    import time
    from pyvirtualdisplay import Display
    from selenium import webdriver
    
    display = Display(visible=0, size=(800, 600))
    display.start()
    
    # now Firefox will run in a virtual display.
    # you will not see the browser.
    browser = webdriver.Firefox()
    browser.get('http://www.google.com')
    time.sleep(30)
    browser.quit()
    display.stop()

However, this works fine, The message box is opened in the virutal screen.

from easyprocess import EasyProcess

from pyvirtualdisplay import Display
 with Display(backend="xvfb") as disp:
     with EasyProcess(["xmessage", "hello"]) as proc:
         proc.wait()

Is there anything I can do?