I wonder if "Hide IP address from trackers" is just private relay, but restricted to tracking websites. Clicking on "Learn more..." there take me to the System Settings Private Relay setting.
Slight distinction between the two. Given the distinction one wouldnt think that hiding from trackers should impact anything beyond ad services but for some reason it did for me. Here is the site where I found this. I would guess the way in which they are hiding from trackers is maybe just in some trickery on the client side in how it handles loading the page vs using the relay.