✅ why does the test case fail?

`public class Solution {
    public int LongestPalindrome(string s) {
        int n = s.Length;
        int maxLength = 1, start = 0;
        for(int i = 0; i < s.Length; i++){
            for(int j = i; j < s.Length; j++){
                int flag = 1;

                for(int k = 0; k < (j-i+1)/2; k++){
                    if(s[i+k] != s[j-k]){
                        flag = 0;
                    }
                }

                if(flag != 0 && (j-i+1) > maxLength){
                    start = i;
                    maxLength = j - i+1;
                }
            }
        }
        return maxLength;

    }
}