Even minor point releases of Visual Studio can cause significant behavior changes and ABI breakages. The full range of defaults that changes inside Visual Studio for a major release may be more than can be accommodated with user options. Switching the Visual Studio “platform toolset” version may be of help.
Switch Visual Studio platform toolset version
In Visual Studio, click Project → Properties → Platform Toolset. If the desired toolset is not present, use Visual Studio Installer to obtain it.
/permissive- VS2019 defaults
/permissive- flag is default in VS2019, but just turning that flag off may not be enough to compile projects from older MSVC versions.
/permissive- flag is under Project → Properties → C/C++ →; Language → conformance mode.