Thank you,

Yes, i see, thanks for the great screen recording.
I agree it is a confusing interface, and difficult to get sites working that depend on third parties.
The list of recently blocked calls can be confusing, since after changing a setting, it is hard to determine what was blocked since the change.

The screen recording is showing how it works, and looks to be working as intended.
This site looks to need all the thirdparty domains except youtube.com enabled to fully display and work.
Even though it is a one off setup per domain, it is a problem if there are many sites like this (and assuming the sites are not refactored again to change domain calls). But at the same time, it protect you again a site introducing tracking later.

This model of managing background calls may never be really suitable for normal use. It is a bit simplistic blocking by domain. It was a bit of an experiment, just trying to follow a philosophy of domain sandbox with the user in control. It maybe needs to allow some things permently, maybe suport URIs not just domains. I get by often by ignoring images, and don't visit many sites, and try to use clean sites (like duckduckgo.com has no cross domain calls).