Maximum length of repeated subarray using recursion and dictionary

I was solving this question using dynamic programming. Since I am not much of a fan of using a table/tabulation so I decided to use dictionary. I wrote this.

class Solution:
    def findLength(self, arr1: List[int], arr2: List[int]) -> int:
        n,m=len(arr1),len(arr2)
        i,j=0,0
        memo={}
        def run(i,j):
            key=(i,j)
            if i>=n or j>=m:
                return 0
            if key in memo:
                return memo[key]
            if arr1[i]==arr2[j]:
                memo[key]= 1+run(i+1,j+1)
                return memo[key]
            memo[key]=max(run(i+1,j),run(i,j+1))
            return memo[key]
        return run(0,0)

This runs fine on the example testcases such as [1,2,3,2,1] [3,2,1,4,7] and [0,0,0,0,0] [0,0,0,0,0]

However it gives a wrong answer on the testcase [0,1,1,1,1] [1,0,1,0,1]

and gives the result as 3 when the correct output is 2

I cannot figure out what I am missing here.