Form editor content sometimes disappears and cannot be brought back

Sometimes when I work on a project, the form editor content suddenly disappears / minimises to such a small dot that I cannot see it anymore. It cannot be brought back, and the problem persists even if I close the project and open it again. Some Korean customers have also reported the same issue.

This essentially turns the project useless, and you need to start all over again.

I have not been able to identify steps to reliably reproduce the issue, but I have an example project where the issue exists.

Steps to reproduce:

1. Download this project 
2. Open Project
3. Open Screen01.ui.qml
4. See issue