✅ P/Invoke, changing values in a struct overwrites overwrites other values

[StructLayout(LayoutKind.Explicit, Size = 16)]
public struct MPVNode
{
    [FieldOffset(0)] 
    public nint StringValue;
    [FieldOffset(0)]
    public int YesNoFlag;
    [FieldOffset(0)] 
    public long IntegerValue;
    [FieldOffset(0)] 
    public double DoubleValue;
    [FieldOffset(0)] 
    public MPVNodeList NodeListValue;
    [FieldOffset(0)] 
    public MPVByteArray ByteArrayValue;
    [FieldOffset(8)] 
    public MPVFormat Format;
}

[StructLayout(LayoutKind.Explicit, Size = 24)]
public struct MPVNodeList
{
    [FieldOffset(0)]
    public int Num;
    [FieldOffset(8)]
    public IntPtr Nodes;
    [FieldOffset(16)]
    public IntPtr Keys;
}

[LibraryImport("libmpv-2", EntryPoint = "mpv_command_node", StringMarshalling = StringMarshalling.Utf8)]
public static extern MPVError MPVCommandNode(MPVHandle ctx, ref MPVNode args, out MPVNode result);

public void Test()
{
    var loadNode = new MPVNode()
    {
        Format = MPVFormat.String,
        StringValue = Marshal.StringToCoTaskMemUTF8("loadfile\0")
    };
    var dataNode = new MPVNode()
    {
        Format = MPVFormat.String,
        StringValue = Marshal.StringToCoTaskMemUTF8("<Path to a video file for now>\0")
    };
    var arr = new[] { loadNode, dataNode };
    var ptr = Marshal.AllocCoTaskMem(Marshal.SizeOf<MPVNode>() * arr.Length);
    for (int i = 0; i < arr.Length; i++) 
        Marshal.StructureToPtr(arr[i], ptr + i * Marshal.SizeOf<MPVNode>(), false);

    var arrayNode = new MPVNode()
    {
        Format = MPVFormat.NodeArray,
        NodeListValue = new MPVNodeList()
        {
           Num = 2,
           Nodes = ptr
        }
    };
    Interop.MPVCommandNode(_handle, ref arrayNode, out var result);
}