We've updated to v188.8.131.52 (from 184.108.40.206)and our users that authenticate via the SSO (Shibboleth)are redirected to wp-login.php to login instead of back to the actual site (ie, browse to mysite.com/site1 WP then redirects them to the SSO authentication but are then redirect to wp-login.php that require another login). Previous version wouldn't require this additional login.
Our network sites are set to 'Only allowed logged in users to see all sites' and we are using the Shibbolize plugin for SSO authentication.
Note: We have another network site setup identical to the one that is broken except that its running 220.127.116.11. I'll be downgrading the plugin to 18.104.22.168 from 22.214.171.124 until this is fixed.