There is also fingerprint.com, which I tend to trust more since it's a company that literally sells fingerprinting tech to other companies.
It managed to identify me while using the Tor browser on "Safer" (doesn't work on "Safest" due to JS). Edit: this is likely due to an issue with my install, and not the browser itself.
Just did a fresh install on Linux (fresh download too) and unfortunately, with no settings changed except security to "Safer", it once again identified me across multiple sessions.
FWIW it does change my ID if I resize the window enough to jump to a different size letterbox.
Edit: forgot to mention, the fresh install got a different ID ti the previous install.
Yeah I'll do some investigating, good to know that the Tor browser isn't at fault though (I probably should've operated under this assumption in the first place).