Extended Tracking on mobile in Unity 2017.3 not working

I have this rather weird issue of Vuforia ignoring the extended tracking functionality on my image Target: - Downloaded and installed Unity 2017.3.1p1 - Created a new Project - Added Vuforia to XR settings - added ARCamera and Image Target with cube attached - configured the image Target to an Image from the website - applied the key in Vuforia config - built that to my android device (Galaxy S6) No matter the bool toggle on the image Target, the cube is gone as soon as the image is out of view. From the setup, this should be a piece of cake, it's just so weird. Do I have to manually configure the minimum android target SDK? is there some important setting in the vuforia configuration I missed? I tested this with Unity 2017.3 because it wasn't working in my actual project under Unity 2017.1 The setup is so easy, I really don't know how to fix this because of that. I'm using a Samsung Galaxy S6 with Android 7.1, Unity has it's default set to API 2.3 (since Vuforia did not complain at any point about this being too low, I though I leave it at that) the exact same app under 2017.1 works with extended tracking on Hololens