在通用单链表中合并排序

排序方面遇到了一些麻烦，在调试时，我发现了有趣的事情，在方法合并返回数据是正确的，然后它连接到 MergeSortLL 方法并显示 Head 只有一个节点在那里，而它必须有 5 个排序节点。我能在这里错过什么？

public static LinkedListNode<T> MergeSortLL<T>(LinkedListNode<T> Head) where T : IComparable<T>
{           
    if (Head == null || Head.Next == null)
        return Head;
    LinkedListNode<T> middle = GetMiddle(Head);
    LinkedListNode<T> half = middle.Next;
    middle.Next = null;
    return Merge(MergeSortLL(Head), MergeSortLL(half));
}
            public static LinkedListNode<T> Merge<T>(LinkedListNode<T> Left, LinkedListNode<T> Right) where T : IComparable<T>
            {
                var mHead = new LinkedListNode<T>(default(T));
                LinkedListNode<T> curr = mHead;
                while (Left != null && Right != null)
                {
                    if (Left.Value.CompareTo(Right.Value) <= 0)
                    {
                        curr.Next = Left;
                        Left = Left.Next;
                    }
                    else
                    {
                        curr.Next = Right;
                        Right = Right.Next;
                    }
                    curr = curr.Next;
                }
                curr.Next = (Left == null) ? Right : Left;
                return mHead.Next;
            }
            public static LinkedListNode<T> GetMiddle<T>(LinkedListNode<T> Head) where T : IComparable<T>
            {
                if (Head == null)
                {
                    return Head;
                }
                LinkedListNode<T> slow, fast;
                slow = fast = Head;
                while (fast.Next != null && fast.Next.Next != null)
                {
                    slow = slow.Next;
                    fast = fast.Next.Next;
                }
                return slow;
            }