Over the period of several years this happened to me on at least half a dozen occasions and recently in a two week period it happened three times.
Fortunately, in my experience this has always been fairly easy to fix, as it just requires submitting a false threat report to Microsoft Defender:
https://www.microsoft.com/en-us/wdsi/filesubmission
Each time this happens I just copy my stock standard false report into the fields of that link and within 24 hours Windows Defender is updated.
Over the period of several years this happened to me on at least half a dozen occasions and recently in a two week period it happened three times.
Fortunately, in my experience this has always been fairly easy to fix, as it just requires submitting a false threat report to Microsoft Defender:
https://www.microsoft.com/en-us/wdsi/filesubmission
Each time this happens I just copy my stock standard false report into the fields of that link and within 24 hours Windows Defender is updated.