Hello
Thank you for your question and reaching out. I can understand you are having issues related to Windows defender service not started.
It looks to be normal behavior of the Threat Protection Service in Windows 11 ,
The threat protection service in Windows 11 is normally OFF and is off (stopped automatically) if not in use. There are other Local Group Policies (gpedit.msc) that affect the operation.
Ultimately the real status of Windows Defender will be listed in Windows Security
Reference ;
https://support.microsoft.com/en-us/windows/virus-threat-protection-in-windows-security-1362f4cd-d71a-b52a-0b66-c2820032b65e
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