Team: Huntress Managed Endpoint Detection and Response
Product: Managed Microsoft Defender
Environment: Windows OS
Summary: Conflicts may occur when running multiple antivirus solutions at once
In short, "you can, but you shouldn't."
By default, in Windows 10 and 11, Microsoft Defender disables itself when a 3rd party AV is detected. Windows Servers do not automatically disable Microsoft Defender when another real-time engine is present, but it's recommended that you disable Microsoft Defender in these scenarios to prevent conflicts. In other words, it's highly recommended to only run one AV at a time!
Please see Microsoft Defender Antivirus compatibility with other security products for more details.