Reproduction steps:
1. Open the attached “IN-88761.zip” project
2. Open the “UI BATCH BUG” Scene
3. Make sure “Incorrect. Interleaved. Not Equal Z, 6 batches” GameObject from the Hierarchy is enabled
4. Open the Frame Debugger (Window > Analysis > Frame Debugger)
5. Expand the “Canvas.RenderOverlays”

Expected result: 2 Draw Calls are visible
Actual result: 6 Draw Calls are visible

Reproducible with: 2021.3.46f1, 2022.3.52f1, 6000.0.26f1, 6000.1.0a3

Reproducible on: Windows 11
Not reproducible on: no other environment tested

Notes:
- Leaving only one type of material GameObjects in the Layout, makes the issue not reproduce anymore
- “Correct. Interleaved. Equal Z, 2 batches” GameObject in the Hierarchy shows the correct behavior while z-position is the same on all GameObjects