Steps to reproduce:
1. Force the attached project "TerrainNormal11.zip" to open with -force-gles32
2. In the Project window under "Assets/Scenes" open "Lit.unity" Scene
3. In the Hierarchy window select the "TerrainNormal" GameObject
4. In the Inspector window open the Terrain Component Settings
5. Enable/Disable Draw Instanced

Expected Results: wave artifacts do not appear on the Terrain when Draw Instanced is enabled
Actual Results: wave artifacts appear on Terrain when Draw Instanced is enabled (See attached DrawInstanced.mp4)

Reproducible with: URP 7.3.1 (2019.4.12f1), URP 8.1.0 (2020.1.9f1), URP 10.0.0-preview.26 (2020.2.0b7, 2021.1.0a2)
Could not test on 2018.4 due to the project breaking when downgrading

Notes:
-Reproduces on Android and Standalone Builds
-Issue does not reproduce in the Editor if the Editor is forced to run in -force-glcore, however it still reproduces on Android
-Issue reproduces in the Editor only when it is forced to run in OpenGLES 3.0, 3.1, 3.2
-Issue does not reproduce on macOS
-In URP 8.1.0 and up the issue does not appear in the Editor, however it still reproduces on Android