Editor doesn't show unsaved changes pop up if editor is being closed when window with unsaved changes is mini

Steps to reproduce:

1. Open attached project
2. Open window by clicking Test > SaveChangesWindow
3. Click Set Unsaved
4. Minimize SaveChangesWindow window
5. Try to close the main editor window

Actual result: Editor closes without informing user about unsaved changes
Expected result: Unsaved changes pop up shows up, informing user that there's a window which has unsaved changes and user is given an option to save or discard changes, or cancel editor close operation.

Not reproducible: Linux or Windows

Reproducible with: 2020.2.7f1, 2021.1.0b11, 2021.2.0a8