Why am i getting NSubstitute.Exceptions.RedundantArgumentMatcherException intermittently?

Question

I am having trouble with NSubstitute when I am running a suite of tests. I intermittently receives the NSubstitute.Exceptions.RedundantArgumentMatcherException: Some argument specifications (e.g. Arg.Is, Arg.Any) were left over after the last call.

As this particular suite only contains the below two unit tests I cannot see i what way I can have these troubles.

public class MyResolverTests
{
    private readonly MyResolver _sut;
    private readonly IObjectClient _objectClientMock;

    public MyResolverTests()
    {
        _objectClientMock = Substitute.For<IObjectClient>();
        _sut = new MyResolver(_objectClientMock);
    }

    [Fact]
    public void IsApplicable_when_something_then_return_true()
    {
        //Arrange
        var myEnum = MyEnum.Value1;

        //Act
        var result = _sut.IsApplicable(myEnum);

        //Assert
        Assert.True(result);
    }

    [Fact]
    public async Task GetSomething_then_return_myobject()
    {
        //Arrange
        _objectClientMock
            .GetAsync<MyObject>(Arg.Any<Guid>(), Arg.Any<string>(), Arg.Any<bool>(),
                Arg.Any<bool>()).Returns(new MyObject()));

        //Act
        var result = await _sut.GetRepresentation(Guid.NewGuid());

        //Assert
        Assert.IsType<MyObject>(result);
    }
}

Have I misunderstood the way it should be used? Is there an incorrect implementation above? From that we have been using MOQ without these troubles to this intermittent problem is disturbing.