Failed to create AreaTargetObserver: TARGET_NOT_FOUND."

I ran into a very strange problem.

I need to manually initialize the Vuforia engine and create the AreaTarger at some point.

I created a test scene with three buttons, which are to load the AR scene (only one AR camera), initialize the AR engine, and create an AreaTarget.

The target status: TRACKED status can be obtained in the test scenario.

The same process, when I put it in the project scene, it will report an error, "ObserverNotCreatedException`1: Failed to create AreaTargetObserver: TARGET_NOT_FOUND.".