You were probably using mobile data (roaming) or hotel WiFi for a hotel approved to host foreigners. Go do it from a residential network.

When I was living in China in 2009, my apartment came with wifi. I noticed I would get shut down often, and made a game of it based on what content I typed in chats to friends back home. But it got old quickly, and then I went to the router in my apartment to reset it and install some custom firmware when I realized the wifi pw they gave me wasn't to the router or modem in my apartment. I factory reset it and had much better access and was able to easily circumvent the great wall after that. Foreigner internet certainly exists, but in my experience it was much more limiting.