Why Moq dependency uprev is not working as expected?

Question

Moq has a dependency hierarchy as follows

Moq 4.18.4
  System.Threading.Tasks.Extensions >= 4.5.4
    System.Runtime.CompilerServices.Unsafe >= 4.5.3

In my application I must use

System.Runtime.CompilerServices.Unsafe to 4.7.0

so from the Moq definition, everything is fine..

Whe I'm trying to execute a unit test that uses AsSpan() from System.Memory, it throws an exception (during Release and Debug mode).

System.IO.FileLoadException
HResult=0x80131040
Message=Could not load file or assembly 'System.Runtime.CompilerServices.Unsafe, 
Version=4.0.4.1, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its 
dependencies. The located assembly's manifest definition does not match the assembly 
reference. (Exception from HRESULT: 0x80131040)
Source=System.Memory
StackTrace:
   at System.MemoryExtensions.AsSpan(String text)
   at UnitTestProject1.UnitTest1.TestMethod1() in 
   C:\source\repos\ConsoleApp9\UnitTestProject1\UnitTest1.cs:line 13

Steps to reproduce:

Create a unit test project with the following nugets:

• Moq Version="4.20.69"
• MSTest.TestAdapter Version="2.2.8"
• MSTest.TestFramework Version="2.2.8"
• System.Memory Version="4.5.4"
• System.Runtime.CompilerServices.Unsafe Version="4.7.0"

Try to run (release or debug) and you'll get an exception on the b = a.AsSpan() line.

namespace UnitTestProject1
{
    using System;
    using Microsoft.VisualStudio.TestTools.UnitTesting;

    [TestClass]
    public class UnitTest1
    {
        [TestMethod]
        public void TestMethod1()
        {
            string a = "asdfdsa";
            var b = a.AsSpan();
        }
    }
}

Is it a bug? or am I missing something?