Just an FYI... We have just implemented single sign-on with our corporate Microsoft Office 365 account. From inside our filewall, access to AGOL works from an Internet Explorer browser, but now fails with Chrome browser. The only answer I could find to resolve this issue was changing settings to disable Extended Protection for Authentication on the server or client side. Our IT is unwilling to make that change for security reasons.
This is too bad, since we found Chrome to be the more stable and reliable browser for AGOL versus IE. I have no experience testing with the Firefox browser.