1. Go to eZ Studio,
2. Click on +Create button,
3. Choose Landing page,
4. In the popup, select any layout,
5. Click on Next button,
6. Fill the page title,
7. Go to the next field by tabbing (click on Tab key on your keyboard),
8. The validation popup appears and this is undesireable action.

The field validation popup should appear only when trying to submit landing page configuration with invalid data.