Describe the bug

Given a struct with an implicit conversion to string (operator overload

public readonly struct AccountKind
{
    private readonly string _value;

    public AccountKind(string value) =>
        _value = value;

    public override string ToString() =>
        _value;

    public static implicit operator string(AccountKind obj) =>
        obj.ToString();

    public static implicit operator AccountKind(string str) =>
        new AccountKind(str);
}

And a test method which accepts it as a parameter via a [DynamicData] attribute:

[TestMethod]
[DynamicData(nameof(GetAccountKinds), DynamicDataSourceType.Method)]
public void TestMethod1(AccountKind kind)
{
  Assert.IsNotNull(kind.ToString());
}

private static IEnumerable<object[]> GetAccountKinds()
{
  yield return [new AccountKind("kind1")];
  yield return [new AccountKind("kind2")];
  yield return [new AccountKind("kind3")];
}

What happens then:

1. Test discovery generates only 1 test:

2. Test execution passes a parameter with value null:

Notes:

1. This doesn't not happen when the assembly is decorated with [TestDataSourceDiscovery(TestDataSourceDiscoveryOption.DuringExecution)]

2. This does not happen when the parameter type is changed to string (see the attached repro for an example)

3. This does not happen when the parameter's type is class

Steps To Reproduce

Attached a sample project: TestProject1.zip

Expected behavior

Test method is executed 3 times, each times receives a parameter with the correct value

Actual behavior

Test method is executed 1 time, it receives a parameter with null

Additional context

<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
<PackageReference Include="MSTest.TestAdapter" Version="3.6.1" />
<PackageReference Include="MSTest.TestFramework" Version="3.6.1" />

VS 2022 version 17.11.5