3D scene drifting from target on certain (android) devices

hey there,

I use Unity 2017.4.6 / Vuforia 7.0.57. After my last tests, some months ago, I'm happy to see, that cloud tracking now works on android / editor as expected. But now I face another strange bug: my testdevice is a samsung s7 (which is in my eyes quite common) and I wondered about a strange drift of the 3D scene from the marker... this was not visible in editor. So I installed it on my Moto Z and... it worked. I created a video for better understanding:

https://youtu.be/lsYJOGyrnXQ

In this case I use a cloud target, but I tested also image targets (on device) and there it's the same problem. Both devices use the same app version.

Maybe in some apps the drift is not so visible, but in my case I put buildings on ground planes and this should be accurate.

Does anyone experienced this bug or have some ideas for a workaround?

For me it seems like a wrong calculation from the android camera aspect /fov - something like that.

I hope the solution isn't again to update unity + vuforia, because everytime I do this, I takes some time to get all things working again and and some point I find a new bug ;) - I like the idea of the LTS support of 2017.4 and really hope to get the app working on a stable version / code base.

best regards Simeon