How to reproduce:
1. Open the attached project “IN-101193”
2. Open the “SampleScene”
3. Enter Play Mode
4. In the Hierarchy, select the “Hip Hop Dancing > MutantMesh” GameObject
5. In the Inspector, turn off the Skinned Mesh Renderer component
6. Observe the Console

Actual result: GraphicsBuffer.IsValid() returns true
Expected result: GraphicsBuffer.IsValid() returns false

Reproducible with: 2023.1.0a3, 6000.0.66f2, 6000.3.6f1, 6000.4.0b6, 6000.5.0a5

Reproducible on: Windows 11
Not reproducible on: No other environments tested

Workaround: Calling SkinnedMeshRenderer.GetVertexBuffer() every frame

Note: Tested using Direct3D11, Direct3D12 and Vulkan Graphics APIs