Windows Defender says "Your IT administrator has not enabled access to this app" on personal Windows 10 Home

Windows Security reports that Microsoft Defender Antivirus is out of date. When I click the warning, I receive the following message:

"Your IT administrator has not enabled access to this app. Contact your IT helpdesk."

I am using a local Windows system, not an organization-managed computer.

1. AMServiceEnabled: True
2. AntivirusEnabled: True
3. RealTimeProtectionEnabled: True
4. AntivirusSignatureLastUpdated: Blank in the copied output
5. AntivirusSignatureVersion: latest version

what would be the cause - anyone experiencing similar -