Using Classic Outlook on Windows for personal email, calendar, and contact management
There is no official solution for the issue. But you can do registry setting below as a workaround.
- Close Outlook,
- Open the reg editor: (In the search box on the taskbar, type regedit, then select Registry Editor (Desktop app) from the results).
- In the registry editor, navigate to the following registry key. HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\ExperimentEcs\Overrides
Locate the “Microsoft.Office.Outlook.Hub.HubBar” string value and set it to “false“. If there isn’t a “Microsoft.Office.Outlook.Hub.HubBar” string value in this registry key, create a new string value in this location called “Microsoft.Office.Outlook.Hub.HubBar” and set it to “false“.
In the meantime, you can submit your feedback through the link: https://feedbackportal.microsoft.com/feedback/forum/89a8afa3-2e1c-ec11-b6e7-0022481f8472