It wouldn't surprise me to find that Windows is now flagging and quarantining unsigned, unfamiliar executables that it catches making these draw calls or really any direct Win32 calls. Microsoft, and in particular Windows Defender which you can't really turn off anymore, has gotten pretty aggressive about blocking software for "security purposes".
Yes, I misremembered some things. Apparently Mono has more compatibility with .NET Framework (for instance 4.81) than dotnet (the current, modern recently released in version 10).
I mixed that up to mean that .NET Framework proper was released as open source, but that's unfortunately not the case.