Bubble in Array-- my algorithm solves the example lists but not the test case

What I have, for the sorting function portion, is this:

def bubble_pass(original):
    counter = 0
    for i, v in enumerate(original[:-1]): #:-1 so it doesn't try to compare the last number to the non-existant one after it
        if v > original[i+1]:
            original[i], original[i+1] = original[i+1], original[i]
            counter += 1
    return counter, original

it gives me the correct solution for the example case (1 4 3 2 6 5), both the number of changes and the checksum. But when I try the actual tests it always fails with too few swaps. Any ideas of what could be going wrong? One thought I had is that it could be about editing a list at the same time as I'm iterating through it... but how do I avoid that without making a new copy of the list for each iteration?

Ah!

I am not sure how the code had been working for me before. You are correct, enumerate creates a separate iterator object and that was the source of the failure. So I fixed it by doing what I was originally trying to avoid, range(len(original)-1).

Thank you! And if you are the creator of the site, thanks so much for making it. I find your tasks much more enjoyable than the ones on similar sites.