Incorrect behaviour when serializing array of tables within table.

[Simie]

I created this repro case:

public class SubTable
{
    public class ListTable
    {
        public int SomeValue { get; set; } = 5;

        public override string ToString()
        {
            return $"ListTable({SomeValue})";
        }
    }

    public List<ListTable> Values { get; set; } = new List<ListTable>();

    public override string ToString()
    {
        return $"SubTable({string.Join(",", Values.Select(p => p.ToString()))})";
    }
}

public class RootTable
{
    public SubTable SubTable { get; set; } = new SubTable();

    public override string ToString()
    {
        return $"RootTable({SubTable})";
    }
}

class Program
{
    static void Main(string[] args)
    {
        var root = new RootTable();
        root.SubTable.Values.AddRange(new[]
            {new SubTable.ListTable() {SomeValue = 1}, new SubTable.ListTable() {SomeValue = 5}});

        Console.WriteLine("Before: {0}", root);


        Console.WriteLine("=== Output TOML: ===");
        var toml = Nett.Toml.WriteString(root);
        Console.WriteLine(toml);
        Console.WriteLine("=== END TOML ===");

        var readRoot = Nett.Toml.ReadString(toml).Get<RootTable>();

        Console.WriteLine("After: {0}", readRoot);

        Console.ReadKey(true);
    }
}

When running I get this output:

Before: RootTable(SubTable(ListTable(1),ListTable(5)))
=== Output TOML: ===

[SubTable]

[[Values]]
SomeValue = 1
[[Values]]
SomeValue = 5

=== END TOML ===
After: RootTable(SubTable())

The deserialized object does not match the original object.
I'm new to TOML so I may be wrong, but I'd expect the output TOML to be this:

[SubTable]

[[SubTable.Values]]
SomeValue = 1
[[SubTable.Values]]
SomeValue = 5

And indeed, reading this TOML returns the correct values:

var testRead =
    Nett.Toml.ReadString(
            "[SubTable]\r\n\r\n[[SubTable.Values]]\r\nSomeValue = 1\r\n[[SubTable.Values]]\r\nSomeValue = 5")
        .Get<RootTable>();

Returns RootTable(SubTable(ListTable(1),ListTable(5)))