We've been on Office 365 since last year and our single sign-on has always worked for Sharepoint online and Exchange. Just recently however, anytime any user goes to our Sharepoint Online Intranet site (or CRM Online for that matter), they get kicked to login.microsoftonline.com first. It has always been this way after clearing browser history/cache on the first login but it is now redirecting to login.microsoftonline.com every time they access domain.sharepoint.com. If they've clicked "Remember Me" then it does, but it still goes to the login page with a button containing their email address that they have to click to login. Has this changed recently? We have not made any internal changes to our environment that would have changed this so I'm wondering if this is now by design.
If so, this poses a huge issue with connecting Sharepoint Contact lists in Outlook as anytime it is accessed, it asks for login.