Inconsistent nested QDockWidget resizing behaviour when docking

Using nested docking when you drag and drop for the first time, the dock is placed next to the other docked widget. If you drag and drop widget to its previous dock space, the next dock will cause other widget to resize.

Attached basic .ui file to reproduce the issue happening in my program

Reproduction steps:

1. Preview .ui file in Designer
2. Drag right dock to the left dock space
3. DockWidget is placed next to the left widget
4. Preview again
5. Drag right dock and place it in right dock
6. Try to drag it to left dock space
7. Left widget is now resized

Example video:
https://www.youtube.com/watch?v=M5DjoWeNXDk