FAKE_GLOBAL API is not supported with overloaded global functions.
But you don't have to use it to fake a global function as you can use the WHEN_CALLED API to control its behavior by passing the overload argument type:
Now after doing this we encountered another problem which is: "Cannot find PDB for: c:\windows\system32\mfc140ud.dll".
Isolator++ needs the PDB file to find and fake the function.
Now we've had success before with setting the env var: set _NT_SYMBOL_PATH=srv*c:\symbols*https://msdl.microsoft.com/download/symbols to prompt the MS EULA to download the necessary PDB files.
For some environmental reason, it didn't work for me.
So I used a PDBDownloader to download the PDB and placed the PDB directly in the build output directory: "$(TargetDir)".
And then it worked fine.