This is why you use Firefox that keeps the cookie jars separate (by default, AFAIK). That should prevent this specific implementation, shouldn't it?
Yes, it should. But this is also why you use uBlock Origin to block tracker scripts.
There are other ways to track. Containers offer a bit mote protection, but the IP address is still visible (unless VPN).
Firefox is my daily on desktop, but on mobile it's Safari. I finally got around to installing uBlock Origin Lite on iOS. I used to run the Firefox version on iOS, but that was discontinued long ago, and I never replaced it. I feel like a bit of an idiot for not doing this sooner.
https://apps.apple.com/us/app/ublock-origin-lite/id674534269...