To whom it may concern,
I have created an app with Unity 2019.1.5f1 and Vuforia 8.1.7 and we are having a great deal of trouble getting the app to work reliably. The hardware being used is an iPad Air 2 (MD792LL/A) with iOS 12.3. When the program is run, the square reticle appears at the start but sometimes it disappears after a few seconds and does not return. If the user taps on the screen while the reticle is visible, a custom crosshair is placed at the position where the user tapped (as it should) but it does not stay in place. It seems to track ok for the first couple seconds but then it starts drifting, occasionally popping into the right location, and eventually it just follows the screen around.
I have advised the user to follow the guidelines at Ground Plane User Guide which they seem to be adhering to.
What might be the problem, we need to get this resolved ASAP.
Thank you for your time.