Unity_BaseInstanceID is always zero when rendering multiple meshes and instancing with the same buffer

Reproduction steps:
1. Open project “BugReport.zip”
2. Open scene “test”
3. Select “GameObject” in the Hierarchy
4. Change the “Batch Size” under the “Render Test (Script)” component through the Inspector
5. Observe Scene view

Expected result: the rainbow is always fully displayed
Actual result: the start of the rainbow repeats

Reproducible with: 2021.3.26f1, 2022.3.0f1, 2023.1.0b19, 2023.2.0a18

Reproducible on: macOS Ventura 13.2.1 (Intel), Windows 10 (by reporter)

Notes:

• Unity_BaseInstanceID is zero, even if a different “startInstance” was provided to “RenderMeshInstanced()” (“RenderTest.cs” line 39)
• If the GameObject does not appear upon opening the project - enter Play Mode
• Also reproducible in Standalone Player