Classificando a primeira coluna do aplicativo treeview enviado com falha

Usei um exemplo de um tutorial para classificar colunas em treeview. Funciona para a 2ª e 3ª coluna, mas não para a 1ª coluna. Se eu clicar no título, recebo este erro:

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Python311\Lib\tkinter\__init__.py", line 1967, in __call__
    return self.func(*args)
           ^^^^^^^^^^^^^^^^
  File "D:\...\Test_Treeview_book.py", line 20, in <lambda>
    tv.heading('#0', text='Name', command=lambda: sort(tv, '#0'))
                                                  ^^^^^^^^^^^^^^
  File "D:\...\Test_Treeview_book.py", line 14, in sort
    itemlist.sort(key=lambda x: tv.set(x, col))
  File "D:\...\Test_Treeview_book.py", line 14, in <lambda>
    itemlist.sort(key=lambda x: tv.set(x, col))
                                ^^^^^^^^^^^^^^
  File "C:\Python311\Lib\tkinter\ttk.py", line 1434, in set
    res = self.tk.call(self._w, "set", item, column, value)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
_tkinter.TclError: Display column #0 cannot be set

Tenho este pequeno programa de teste como referência e não consegui encontrar a falha. Agradeço qualquer dica para resolver esse problema ou não é possível ordenar a 1ª coluna porque é uma árvore?

import tkinter as tk
from tkinter import ttk
from pathlib import Path

root = tk.Tk()

root.grid_rowconfigure(0, weight=1)
root.grid_columnconfigure(0, weight=1)

paths = Path('.').glob('**/*')

def sort(tv, col): # Doesn't work on 1st column '#0'
    itemlist = list(tv.get_children(''))
    itemlist.sort(key=lambda x: tv.set(x, col))
    for index, iid in enumerate(itemlist):
        tv.move(iid, tv.parent(iid), index)

tv = ttk.Treeview(root, columns=['size','modified'], selectmode=None)

tv.heading('#0', text='Name', command=lambda: sort(tv, '#0'))
tv.heading('size', text='Size', anchor='center', command=lambda: sort(tv, 'size'))
tv.heading('modified', text='Modifies', anchor='center', command=lambda: sort(tv, 'modified'))

tv.column('#0', stretch = True, anchor='w')
tv.column('size', width=100, anchor='center') 
tv.column('modified',anchor='center')

tv.grid_rowconfigure(0, weight=1)
tv.grid_columnconfigure(0, weight=1) 
tv.grid(row=0, column=0, sticky='nsew')
#tv.pack(expand=True, fill='both')

for path in paths:
    meta = path.stat()
    parent = str(path.parent)
    if parent == '.':
        parent = ''
               
    tv.insert(parent, 'end', iid=str(path), text=str(path.name), values=[meta.st_size, meta.st_mtime])

scrollbar = ttk.Scrollbar(root, orient=tk.VERTICAL, command=tv.yview)
tv.configure(yscrollcommand=scrollbar.set)
scrollbar.grid(row=0, column=1, sticky='nse') #scrollbar goes not to the left!
        
root.mainloop()