I noticed that my function is quite different from everyone else's but it works. Is there a flaw I don't see however?

import random

CELLS = [(0, 0), (0, 1), (0, 2),
         (1, 0), (1, 1), (1, 2),
         (2, 0), (2, 1), (2, 2)]


def get_start_locations():
    # monster = random
    loc_monster = random.choice(CELLS)

    # door = random
    loc_door = random.choice(CELLS)

    # player start location= random
    player_start = random.choice(CELLS)

    # if monster, door, or start are the same, do it again
    if loc_door == player_start:
        get_start_locations()
    elif player_start == loc_monster:
        get_start_locations()
    elif loc_monster == loc_door:
        get_start_locations()
    else:
        return loc_monster, loc_door, player_start


def update_location(tpl, char):
    first_coord, second_coord = tpl
    if char == 'U':
        first_coord -= 1
    elif char == 'D':
        first_coord += 1
    elif char == 'R':
        second_coord += 1
    elif char == 'L':
        second_coord -= 1
    new_coord = (first_coord, second_coord)
    if test_move(new_coord):
        return new_coord
    else:
        return tpl


def test_move(tpl):
    first_coord, second_coord = tpl
    if first_coord not in range(0, 3):
        return False
    elif second_coord not in range(0, 3):
        return False
    else:
        return True

monster, door, player = get_start_locations()
# print(monster)
# print(door)
# print(player)

while True:
    print("Welcome to the dungeon!")
    print("You're currently in room {}".format(player)) # fill in with player current position
    print("You can move 'U' up, 'D' down, 'R' right, 'L' left")
    print("Enter QUIT to quit.")

    move = input("> ")
    move = move.upper()

    if move == 'QUIT':
        break

    # if it's a good move, change the player's position
    new_player = update_location(player, move)
    if new_player != player:
        player = new_player
    # if it's a bad move, don't change anything, display msg
    else:
        print("Can't move in the {} direction you're at the edge".format(move))
    # if the player's new position is the door, they win
    if player == door:
        print("You found the door, you win!")
        break
    # if the player's new position is the monster, they lose
    elif player == monster:
        print("You lose! Eaten by a monster")
        break
    # otherwise, continue
    else:
        continue