Multiple Same Numbers Entered in Guessing Game; Loop Stops Working?

I've been making a 4 number guessing game to learn python that meets three criteria:

• replayable
• tells player how many tries it took to guess correct answer
• tells player how many numbers are correct to steer player to right answer

I thought I met the criteria but there is this really weird bug that happens in the game. If you try to guess the number using trial and error; the game breaks and doesn't detect that your answer is right. If the answer is '[1, 2, 3, 4]' and you try to get the answer by doing '[1, 1, 1, 1]' then '[1, 2, 2, 2,]' and eventually get '[1, 2, 3, 4]'; the program will say that the 4 numbers match but it won't let you win the game and just asks you to play again. This bug has been really killing me and I hope the person reading understands what I'm trying to say.

Sorry about the big long block of code but, the problem could be anywhere here but I honestly cannot see it; I will annotate as best as I can to make it look less confusing. I just... why is this happening!?

def compareLists(a, b): # to compare the guessed numbers and random numbers
    return list(set(a) & set(b))
rNums = random.sample(range(10), 4) # random list of numbers
def start():
    count = 0 # count for number of tries
    global rNums
    gNums = [] # guessed numbers
    print(rNums) # cheating to save time
    flag = True # to stop the guessing loop

    while flag:
        print("Get ready to guess 4 numbers!")
        for i in range(0, 4): # asks the player 4 times to input a number
            x = int(input("Guess: "))
            gNums.append(x) # puts numbers in guessed numbers

        comparison = len(compareLists(rNums, gNums)) # storing the length of the list of similar numbers
        isCorrect = gNums == rNums # to check if lists are the same
        print("You guessed: ", gNums) # telling player what they have guessed

        if isCorrect: # if the lists are the same

            if count > 1:
                print("You win!! It only took you %d tries!" %count) # telling the player how many tries it took
            else: #congratulating the player on a flawless guess
                print("I CAN'T BELIEVE WHAT I'M SEEING!!!")
                print("YOU GOT IT IN ONE GO!!")
            count += 1 # increment count
            rNums = random.sample(range(10), 4) # generate new numbers
            gNums.clear()
            pAgain = input("Play again?")
            if pAgain.lower() in ('y', 'yes'): # replaying the game
                continue
            elif pAgain.lower() in ('n', 'no'):
                flag = False
            else:
                print("Incorrect syntax!")

        else:
            print("You guessed " + str(comparison) + " numbers right, keep guessing!") # tells the player how many numbers are similar so the player can get a more educated guess
            gNums.clear() # empties guessed numbers
            count += 1 # increment count
            print("Number of tries so far: %d" %count) # showing player number of tries so far