Exact Device Model number: SM-N9300, stock ROM from HK area
The issue be reproduced using the Vuforia Unity Extension
Device orientation: Portrait and landscape
Camera: the issue be reproduced using the Back camera and the Front camera
didn't test but our test scene in unity only contains ARCamera, nothing else.
Concurrent camera access:
vuforia testing app is the only one that accesses the camera.
Occurence vs. Internet connection:
with or without internet connection, this issue persists.
The issue is that the phone camera doesn't autofocus.
the same testing app has been installed on various other devices including samsung s6 and many other brands, they all do well.