There is an Outlook issue with the New/Web version of Outlook. We are aware, but please be patient as this is a Microsoft issue.
If you have the full client of Outlook, switch to Outlook Classic. The Classic version is working properly.
To switch:
In the Search Bar, type in Outlook
You will see an Outlook (classic) and an Outlook (new)
Select the Classic
You can then pin it to you task bar
Right click on the Outlook icon on your taskbar and selecting Pin to Taskbar