Possible bug in 2nd functions challenge

So I've written code for the TeamTH UI for the 2nd functions challenge in the Python Basics class, that says that the return my function returns is wrong. TeamTH says that it returns None instead of the desired solution of "The sum of [1,2,3] is 6". However when I test my code on my Mac's terminal, I get the desired solution. I have attached my code below as well as an attachment.

def add_list(list): sum=0 for each in list: sum = each+sum return sumdef add_list(list): sum=0 for each in list: sum = each+sum return sum

def summarize(list):

print("The sum of {} is {}.".format(list,numz))

list = [1,2,3] numz = add_list(list) summarize(list)

# add_list([1, 2, 3]) should return 6
# summarize([1, 2, 3]) should return "The sum of [1, 2, 3] is 6."
# Note: both functions will only take *one* argument each.

def add_list(list):
  sum=0
  for each in list:
    sum = each+sum
  return sum

def summarize(list):
  print("The sum of {} is {}.".format(list,numz))

list = [1,2,3]
numz=add_list(list)
summarize(list)