力扣 回文链表，我写的递归怎么是错的

https://leetcode-cn.com/problems/palindrome-linked-list/solution/hui-wen-lian-biao-by-leetcode/

官方答案递归：

class Solution {

    private ListNode frontPointer;

    private boolean recursivelyCheck(ListNode currentNode) {
        if (currentNode != null) {
            if (!recursivelyCheck(currentNode.next)) return false;
            if (currentNode.val != frontPointer.val) return false;
            frontPointer = frontPointer.next;
        }
        return true;
    }

    public boolean isPalindrome(ListNode head) {
        frontPointer = head;
        return recursivelyCheck(head);
    }
}

我写的感觉执行过程是一样的啊，看懵了，大佬们帮忙看看。

class Solution {
    private ListNode frontPointer;

    private boolean recursion(ListNode currentNode){
        if (currentNode.next == null){
            return true;
        }
        if (!recursion(currentNode.next)) 
            return false;
        boolean result = frontPointer.val == currentNode.val;
        frontPointer = frontPointer.next;
        return result;
    }

    public boolean isPalindrome(ListNode head) {
        frontPointer = head;
        return recursion(head);
    }
}

输入： [1,2] 输出： true 预期结果： false