Outlook Focused Inbox

Outlook.com Focused Inbox feature seems to cause eM client to slow down.  
Behavior seen:  Inbox messages take a very long time to download and the application is always Synchronizing.
Action taken:  In Outlook.com, I used the Options Mail/Layout/Focused inbox screen to disable the feature (Don’t sort messages), and my eM client is working great.
Has anyone else seen this?