[Python] Double counting problems for Ising model I am trying to make (counting diagonally)

I was trying to make a python code for calculating the energy (Hamiltonian). By having a matrix (state with 1's and -1's), my plan is to go through each element to its nearest diagonal neighbours and sum them (weighted). But my results differ when I count differently (this seems to be a result of double counting). I manually calculated what I got with the states I receive (the lowest possible energies) and it gives me an answer of -36 but the code gives -64.

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
from itertools import product

size = 4 #Size of model
beta = 2 #Constant parameter (for later)
J = 1

def energy2(matrix):
engsum2 = 0
for i in range(size):
for j in range(size):
leftup = matrix[(i-1) % size, (j+1) % size]
leftdown = matrix[(i-1) % size, (j-1) % size]
rightup = matrix[(i+1) % size, (j+1) % size]
rightdown = matrix[(i+1) % size, (j-1) % size]
s = matrix[i,j]
e_n2 = s*rightup + s*rightdown + s*leftup + s*leftdown
engsum2 = e_n2 + engsum2
return J * engsum2

matrices = product([1, -1], repeat=size*size) #Produces all combinations of the matrix states
matrices = np.reshape(list(matrices), (-1, size, size)) #Reshapes them, makes it easier to manipulate
engs2 = []

for j in range(2**(size*size)):
engs2.append(energy2(matrices[j]))

engs2 = np.array(engs2)
mineng2 = np.min(engs2)

print("The state(s) with the minimum energy is/are:", matrices[engs2 == mineng2,:,:],"With the energy of,", mineng2)```

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