Assigned shader changes cannot be undone in Output Mesh

How to reproduce:

1. Import the attached project
2. Open Mesh Output vfx
3. Open shader obejct picker
4. Assign shader A
5. Then assign shader B
6. Press CTRL + Z

Expected result: shader can be undone

Actual result: shader remains the same in the shader field

Not reproducible with GPU outputs (primitives, mesh)