I don't understand what can happen for you.
I tested again with another browser, 'en-US' as unique preferred language. Cookies are all suppressed. I go to your site and I am correctly redirected to the English page as expected.
I don't understand what can happen for you.
I tested again with another browser, 'en-US' as unique preferred language. Cookies are all suppressed. I go to your site and I am correctly redirected to the English page as expected.