Python: urllib.request.urlopen() aways returns an error

I am trying to write a Python code like below:

import urllib.request

url = 'http://example.com/'

req = urllib.request.Request(url)
try:
    with urllib.request.urlopen(req) as res:
        body = res.read()
except urllib.error.HTTPError as e:
    print(f"http error: {e.code}")
except urllib.error.URLError as e:
    print(f"url error: {e.reason}")

It returns an error which I cannot find a resource on:

url error: [Errno 26] Operation in progress

I've tried this in Safari 17.5 and Chrome 126.0.6478.183.

I'm using an M1 MacBook Air from 2020