So sorry for that trouble! This is a known issue we're working on resolving with the outlook.com team directly. For now, the solution is to delete and re-add your account.
Please go to Settings, select the affected account, and select Delete Account. When you re-add the account, the proper settings will be imported and everything should work as intended. If you're still having issues, please don't hesitate to reach us at support: Settings > Help & Feedback > Contact Support.