@ Groucho1943
Your machine now has a working / viewable App & Browser Control. correct ?
as to your other issue, for your benefit:
As regards tamper protection on Microsoft Defender.
We have previously run the Powershell's Get-MpComputerStatus command-let and it indicated that that protection is on.
IsTamperProtected is True
RealTimeProtectionEnabled is True
Conclusion, tamper protection is on.
As to the Windows registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Defender\Features
The value TamperProtection on your system is 1
which means that it is ON
The value TamperProtectionSource on your system is 5
which means it uses the Windows MS Defender signatures for protection
That is standard and normal.