When I am running python scripts to test a website on Headless Chrome Broswer (Webdriver + Selenium), we often get a timeout error, I found out the problem occu
I was having a similar problem, normal Chrome driver worked fine, but headless chrome always timed out.
I found out that for responsive web pages, you need to set the window size:
driver.set_window_size(1200, 600)
It worked after adding this line just after initialization of the driver itself.
I hope this helps!