Use of animators within StackView items causing segfaults

We are experiencing segmentation faults while using the StackView component along with animators. We have narrowed it down to a simple example (main.qml) attached.

To reproduce using the attached example:
1. Rapidly click on the UI and stop (could be as little as two clicks)
2. Observe crash

This was previously fixed with, but later reverted:
https://codereview.qt-project.org/#/c/186430/