Python - Actualizando matriz

board=[

[1,2,3],

[4,"X",6],

[7,8,9],

]

def DisplayBoard(tablero):

    for x in board:

        print("+","-"*9,"+","\n|   |   |   |")

        for y in x:

            print(f"| {y} ",end="")

        print("| \n|   |   |   |")

    print("+","-"*9,"+")

DisplayBoard(board)

def EnterMove(tablero):

    pos=int(input("Por favor ingresa tu movimiento:"))

    for i in tablero:

        for j in i:

           if j==pos:

               j="O"

    return tablero

board1=EnterMove(board)

DisplayBoard(board1)

board=[[1,2,3],[4,"X",6],[7,8,9],]

def DisplayBoard(tablero):

    for x in tablero:

        print("+","-"*9,"+","\n|   |   |   |")

        for y in x:

            print(f"| {y} ",end="")

        print("| \n|   |   |   |")

    print("+","-"*9,"+")

DisplayBoard(board)

def EnterMove(tablero):

    pos=int(input("Por favor ingresa tu movimiento:"))

    for t1,i in enumerate(tablero):

        for t2,j in enumerate(i):

            if tablero[t1][t2] == pos:

                tablero[t1][t2]="O"

                return tablero

board1=EnterMove(board)

DisplayBoard(board1)

ya probe el codigo y sí funciona pero no actualiza el valor de la matriz

#-*- coding: utf - 8 -*-

board=[

[1,2,3],

[4,"X",6],

[7,8,9],

]

def DisplayBoard(tablero):

    for x in tablero:

        print("+","-"*9,"+","\n|   |   |   |")

        for y in x:

            print(f"| {y} ",end="")

        print("| \n|   |   |   |")

    print("+","-"*9,"+")

DisplayBoard(board)

def EnterMove(tablero):

    pos=int(input("Por favor ingresa tu movimiento: "))

    fila = 0

    for i in tablero:

        columna = 0

        for j in i:

            if j == pos:

                tablero[fila][columna]="O" #para cambiar el elemento hay que pasarle la ubicación en la matriz no el valor en si

            columna+=1

        fila+=1

    return tablero

board1=EnterMove(board)

DisplayBoard(board1)