Steps to reproduce:
1. Create new Unity project using HDRP 3D Template
2. Create Material in Project window
3. Create Empty GO in Hierarchy window
4. In Inspector Add Line Renderer Component for Empty GO
5. In Line Renderer Component > Materials add recently created Material
6. Press “+” to add another Material
7. Make sure that Element 1 Material is set to None
8. Observe the Line in Scene/Game view
9. Repeat these steps using URP 3D empty project

Actual results: In HDRP 3D Template, Line Renderer is flickering when one of the two Materials are set to None in the List

Expected results: Line Renderer should render only first Material, there should be no flickering in Scene/Game view

Reproducible with versions: 6000.0.59f1, 6000.2.7f1, 6000.3.0b4, 6000.4.0a1

Tested on (OS): macOS Silicon, Tahoe 26.0 (M1)

Notes: In URP, when second Material is empty, the first Material is rendered instead, no flickering is happening the Scene/Game views