Microsoft Outlook (Version 2401 Build 16.0.17231.20194) includes an issue that prevents Outlook from retrieving data from ActiveSync servers. As of February 29, 2024, Microsoft has fixed the issue in Outlook Desktop version 2402 Build 17328.20068 and higher. To install the update, launch Microsoft Outlook and select File | Office Account | Update Options | Update Now.
If you worked around the issue by reverting to an earlier version, you can re-enable updates by selecting File | Office Account | Update Options | Enable Updates.
Alternatively, you can use a different mail protocol to connect to the server, such as IMAP or MDaemon Connector, or switch to a different mail client, such as MDaemon Webmail or eM Client.
More information can be found here: https://support.microsoft.com/en-us/topic/da2dc0dd-297e-48ba-b6d9-ab18f5d522fc
