xUnit System.TypeLoadException when implementing interface with dynamic method param

Question

I have a referenced nuget package that contains an interface:

public interface IMyInterface {
    bool Initialize(Dictionary<string, dynamic> initArguments);
}

In my solution I have this implementation:

public class MyImplementation : IMyInterface 
{

    public bool Initialize(Dictionary<string, dynamic> initArguments) 
    {
        return true;
    }
}

If I use it in a console project, it works without problem:

var myImplementation = new MyImplementation();

But i if try to use it in a unit test project is throws this:

System.TypeLoadException : Method 'Initialize' in type 'xxx.MyImplementation' from assembly 'xxx, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null' does not have an implementation.

This is my unit test:

    [Fact]
    public void Test1()
    {
        var myImplementation = new MyImplementation();

        Assert.NotNull(myImplementation);
    }

I think it is maybe because the Dictionary<string, dynamic> parameter, something related to that dynamic but not sure. I have google it a lot without luck.

Update

If I check the interface referenced from nuget package it is like this:

public interface IMyInterface {
    bool Initialize([Dynamic(new[] { false, false, true })] Dictionary<string, dynamic> initArguments);
}

I dont know what why the compiled version of the nuget package is like that, with the Dynamic data attribute in the param.