There is a bug in the fixlet “UPDATE: Microsoft .NET Framework 4.8 Available - Windows 7 SP1 / Windows 8.1 / Windows 2008 R2 SP1 / Windows 2012 / Windows 2012 R2 / Windows 10 / Windows Server 2016 / Windows Server 2019” (ID: 48001). Relevance 7 needs to include both 1903 and 1909 in the if statement. Both have .NET 4.8 installed natively and will show 528040 for that registry value.