Splat map area of terrain with more than 4 textures isn't rendered on right eye when using Multipass render mode

Reproduction steps:
1. Open the attached project ("VrTester.zip")
2. Enter Play mode

Expected result: Right eye splat map area of the terrain is rendered
Actual result: Right eye splat map area of the terrain isn't rendered

Reproducible with: 2020.3.22f1, 2021.1.28f1, 2021.2.2f1, 2022.1.0a15
Could not test with: 2019.4.32f1 (textures corrupted)

Tested:

• MockHMD
• OpenXR (Oculus Rift S)