да, только что наткнулся на ответ от админов сайта.
Free accounts' internet access goes via a proxy "whitelist". Here is the list of sites currently allowed: https://www.pythonanywhere.com/whitelist/
We operate this to prevent malicious users from using our site to hack into and spam other websites. Paid-for accounts don't have this limitation, because we can connect them to real people. Spammers and criminals prefer to be anonymous, so we figure they're unlikely to sign up for paid accounts here.
