Automapper execution plan unchanged

Automapper.cs

static void Main(string[] args)
{
	var caseView = new CaseView(){
			User = new UserView{
				UserID = 5
			},
			UserID = 5
		};
		
	Mapper.Initialize(cfg =>
	{

		cfg.AddProfile(typeof(CaseProfileDefaultMap));
	});
	var configuration = new MapperConfiguration(cfg => cfg.CreateMap<CaseView, Case>());
	var executionPlan = configuration.BuildExecutionPlan(typeof(CaseView), typeof(Case));

	var result1 = Mapper.Map<CaseView, Case>(caseView);

	Mapper.Reset();
	Mapper.Initialize(cfg =>
	{

		cfg.AddProfile(typeof(CaseProfileWithNull));
	});
	var configuration2 = new MapperConfiguration(cfg => cfg.CreateMap<CaseView, Case>());
	var executionPlan2 = configuration.BuildExecutionPlan(typeof(CaseView), typeof(Case));
	
	var result2 = Mapper.Map<CaseView, Case>(caseView);
		
	// Compare execution plans
	
	// Either the plans are the same, and the values are the same:
	executionPlan.ShouldBe(executionPlan2);
	((int?)(result2?.User?.UserID)).ShouldBe((int?)(result1?.User.UserID));

	// Or the plans are different
	executionPlan.ShouldNotBe(executionPlan2);
}

public class UserView {
	public int UserID {get; set;}
}
public class User {
	public int UserID { get; set; }
}

public class UserChild : User {
	
}

public class Case
{
	public virtual User User {get; set;}
	public int? UserID {get; set;}
}

public class CaseView
{
	public UserView User {get; set;}
	public int? UserID {get; set;}
}

public class CaseProfileDefaultMap : Profile {
	public CaseProfileDefaultMap()
	{
		CreateMap<CaseView, Case>();
		CreateMap<UserView, User>();
	}
}


public class CaseProfileWithNull : Profile
{
	public CaseProfileWithNull()
	{
		CreateMap<CaseView, Case>()
			.ForMember(x => x.User, opts => opts.MapFrom(src => (User)null));
		CreateMap<UserView, User>();
	}
}