Parent-child hierarchy breaks when a prefab is created from missing child instance of the same prefab. Refer the attached videos from 2019.3.0a5 and 2019.2.0b4.

Steps to reproduce:
1) Create a new project
2) Create an empty gameObject "A"> Create a prefab out of it.
3) Drag the prefab to hierarchy as child of "A".
4) Delete the prefab from the project.
5) Drag the child to the project folder to make a prefab.

Actual result: Prefab is created but the parent-child hierarchy breaks.
Expected result: Parent-child hierarchy shouldn't break.

Occurs on: 2019.3.0a5, 2019.3.0a1.
Working fine on: 2019.2.0b5

Environment: Both Windows and Mac