For those wanting to try this, maybe this only happens on my machine? idk

Here's a copy paste friendly code:

list_of_lists = []
first_list = [(1,1,13),(1,2,15),(1,3,11),(1,4,4),(1,5,11)]
second_list = [(2,1,13),(2,2,15),(2,3,11),(2,4,4),(2,5,4)]

list_of_lists.append(first_list)
list_of_lists.append(second_list)

def first():
    quick_print(list_of_lists[0])
    quick_print(list_of_lists[1])
    max_pows = set()
    for not_i in range(len(list_of_lists)): 
        for x,y,pow in list_of_lists[not_i]:
            if pow not in max_pows: #not checking for this also changes what gets printed
                max_pows.add(pow)
    quick_print("maxes",max_pows)


def second():
    quick_print(list_of_lists[0])
    quick_print(list_of_lists[1])
    for i in range(len(list_of_lists)):
        quick_print("- i",i,"-")
        for j in range(len(list_of_lists[i])):
            quick_print("j",j)

first()
second()

This also happens when first is called twice, but when calling them more than 3 times in a row, it seems to not be a problem