How to reproduce:
1. Open the attached "Decal-Unity-2022.3.32.zip" project
2. Open the "SampleScene"
3. In the Assets folder, navigate to “Settings” and locate “DecalMaterial”
4. In the Inspector window, under “Advanced Options”, locate “Enable GPU Instancing” and uncheck the box
5. Observe the result in the Game or Scene window
6. Locate “Enable GPU Instancing” again and check the box
7. Observe the result

Expected result: all three decals should be visible on the plane
Actual result: two out of three decals disappear

Reproducible in: 2022.3.1f1, 2022.3.36f1
Not reproducible in: 2021.3.40f1, 2022.3.0f1, 2022.3.38f1, 6000.0.11f1
Fixed in: 2022.3.37f1

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Notes: the “GPU Instancing” checkbox behaves inconsistently as soon as Play mode is entered. If initially the box is checked, unchecking it will result in the decals disappearing so long as Play mode isn’t active. If Play mode is then activated when the decals are still invisible, they will reappear inside Play mode, and checking the box will instead make them disappear. Exiting Play mode at this state sometimes stops the decals from disappearing altogether.