Z-Index Behaviour is not respected when editing UI in the viewport

Hello,

When setting the Z-Index behaviour to “Sibling”, an object parented to any other object will not be selectable over its parent if its Z-Index is lower, despite being rendered above its parent due to how the Sibling property behaves.

In the example file, notice how the blue label does not get selected and instead its parent, red, gets selected.

Thank you!

Technical info
CPU: AMD Ryzen 7 4800H with Radeon Graphics (2.90 GHz-4GHz)
GPU: Nvidia GeForce RTX 2060 6GB
RAM: 16GB

Enabled beta features:

  • Aerodynamics
  • Dragger QoL Improvements
  • EditableImage and EditableMesh
  • Face Capture
  • Faster Play Solo
  • Grass Length Customization
  • Live Animation Creator
  • Material Generator
  • Multilayer Wrap Fix
  • New Audio API
  • Notched Screen Support
  • Path2D Instance
  • Texture Generator
  • Updated Docking System
  • Updated Roblox Controls
  • Upgraded Shorelines
  • Video Uploads

Reproduction files: Please find a sample file. z-index problems.rbxl (55.5 KB)

Expected behavior

Selection in the viewport should be based over how it is currently displayed. In other words, if a UI appears above another, it is only intuitive that you would select the UI in question when clicking its parent.