I'm having trouble with the newer versions of vuforia (9.x.x), including the last one.
I don't know why but the image tracking is worse than older version.
I've tested the same unity app with the same image target with vuforia 8.5.8 + unity 2018 and vuforia 9.7.5 + unity 2020.
unity 2018 + vuforia 8 is much better!
So, Vuforia Team, would you please let us download older versions of vuforia?
I've got a license and cant use it with the new vuforia versions because its not reliable for my clients.