At random during the day one of my users Outlook is not show all unread messages in the Inbox. For example, in Outlook the unread message count would show as 2 unread emails. same on his iPhone. However in the Inbox only one unread message appears. If he clicks on another folder then back to Inbox it appears. Or if he toggles between the All and Unread buttons the unread email appears. This occurs at random with different emails. The behavior is as though a screen refresh is required to show the unread email. But this occurs at random, not with all unread messages.
Steps done so far: - Reset the views - Created a new Outlook user profile Outlook is connected online to an on-premise Exchange 2016 server.