Unity 2017.3 with Vuforia built-in. iPhone 7 Plus with iOS 11.2.
Using image tracking. Works great to detect my image tracker, and tracks it well without much jitter.
However, after about 20 seconds of using the app, the camera view begins to lag about 1 second behind actual device movement. This lag occurs whether I am pointing the camera at a tracker or not. I've gone through every single optimization and setting possible to eliminate this (I'm Unity certified, for what it's worth). Nothing works to fix the lag.
I have no other features in the app aside from detecting the tracker. My image tracker has a Unity Sphere primitive as a child. No other scripts, logic or GameObjects.
Even with the excellent tracker recognition, this is a show-stopping bug.
If anyone has developed a Vuforia app in Unity 2017 for iPhone, please share how you worked around this issue.