How to reproduce:
1. Create and open a new URP / HDRP project
2. In Hierarchy create UI > Panel
3. Select the Panel GameObject and scale it down to see the borders
4. Make the Game view window a floating window
5. Resize the Game view window by any corner

Expected result: The panel remains in the center while the window is resized
Actual result: The panel stays attached to the bottom-left corner of the rendered view while the window is resized

Reproducible with: 2023.3.0a12, 6000.0.37f1, 6000.1.0b5, 6000.2.0a2
Not reproducible with: 2022.3.57f1, 2023.3.0a11

Reproduced on: Windows 11 Pro (23H2)
Not reproduced on: No other environment tested

Note: Reproducible in URP and HDRP but not in BiRP