Csharp 带有可选参数的模拟方法返回意外的不同值，具体取决于可选的默认值

I mock a method from an interface which has optional parameters to return true.
However, depending on whether I pass all the optional parameters to the call or only the required parameters I get a different result.

以下是该行为的完整工作示例:

using Moq;
using System.Threading;
using System.Threading.Tasks;
using Xunit.Abstractions;
namespace MoqTest
{
    public interface IProcedureService
    {
        Task<bool> InterfaceMethod(string req1, int req2, int? opt1 = null, CancellationToken opt2 = default);
    }
    public class Tests
    {
        Mock<IProcedureService> _procedureService = new Mock<IProcedureService>();
        ITestOutputHelper _output;
        public Tests(ITestOutputHelper output) => _output = output;

        [Xunit.Fact]
        public async void DoTheTest()
        {
            _procedureService.Setup(x => x.InterfaceMethod(It.IsAny<string>(), It.IsAny<int>(), It.IsAny<int>(), It.IsAny<CancellationToken>()))
                .ReturnsAsync(true);

            _output.WriteLine($"result from IsUniqueProcedureNameInWorkspace (using optional defaults) " +
                $"{(await _procedureService.Object.InterfaceMethod("", 0))}"); // returns false
            _output.WriteLine($"result from IsUniqueProcedureNameInWorkspace (NOT using optional defaults) " +
                $"{(await _procedureService.Object.InterfaceMethod("", 0, 0, default))}"); // returns true
        }
    }
}

这将输出以下内容:

Standard Output: 
result from IsUniqueProcedureNameInWorkspace (using optional defaults) False
result from IsUniqueProcedureNameInWorkspace (NOT using optional defaults) True

I would expect them to both return True as I set It.IsAny for all the parameters in the Setup.
What am I missing here?

我的Moq版本是4.20.70