I've changed all the connection strings I could find in my company old ASP.NET application but it still points to the same database

Question

I'm trying to change the database of a local application but it keeps pointing to the old database (I renamed some tables to check if it breaks after and it does). I've searched for the connections strings inside the application and renamed them all to the new database, but it keeps pointing to the old one. I know the app is being refreshed cause I'm able to break it by removing lines from the web.config. No matter what I do, it keeps pointing to the old database.

Does IIS keeps connection strings cached somewhere? Any clues where the connection strings might be?

Another interesting thing is that even when I remove all the old connection strings the app still works. The app is using ASP.NET and IIS.