Vuforia unity Scene loading issues - taking longer

Hi

I am using unity for android in order for an AR app.

I have nearly 14 image targets in the same scene. Using 3 dataset active.

When i jump to another scene and return back to the home scene (main scene) . the loading of main scene takes too long.

For this reason, the click of the back button, remains in that screen for too long before it goes to the main scene.

Any suggestion on this to be immediate navigation to main scene.

These are the thing I tried.

Tried with an  empty scene without AR camera but still same loading issue.

Tied deleting some of 3d objects (models) and retained only one model - still the same loading issue.

Thanks.