New information. Safari ad and other content blockers rely an API for access to Safari traffic. When Apple came up with the ability to enable/disable content blocking on a site by site basis they deprecated they created a new API to support the site by site content blocking. Some developers have already switched to the new API but others have not. If the content blocker is still using the old API Safari's enable/disable content blocker switch cannot work which would account for the differences Artie505 and I are seeing. Eventually Apple will turn off the old API and those content blockers that have not switched will no long work at all.
NOTE:
This applies ONLY TO SAFARI EXTENSIONS and not to ad blocker apps or VPNs that operate outside of the Safari environment.
The latest AdGuard extension offers the option of using the old or new API. There may be others I am unaware of — I haven't installed and tested every content blocking Safari extension.
"All you've got to do is own up to your ignorance honestly, and you'll find people who are eager to fill your head with information" --Walt Disney
Ghostery hasn't issued any updates recently, but although AdBlock just issued one, I'm unable to test it at the moment, because I had issues with it and reverted.
I'll update as new info becomes available.
The new Great Equalizer is the SEND button.
In Memory of Harv: Those who can make you believe absurdities can make you commit atrocities. ~Voltaire