PixelNormalWS node not working with Substrate

Summary

The PixelNormalWS node in the material graph outputs the same as the VertexNormalWS node when connected to a Substrate slab without taking into account the normal maps connected to the same slab. (Tested with Substrate Slab BSDF and Substrate Toon BSDF). This is different from non substrate behavior where the normal map effect is included.

What Type of Bug are you experiencing?

Rendering (Graphics / Niagara)

Steps to Reproduce

Create a new project in Unreal 5.8
Create a new material
Add a PixelNormalWS node, a normal map texture, and a Substrate Slab BSDF - Simple
Connect Normal Map RGB pin to Normal Input on Substrate slab
Connect PixelNormalWS output pin to Base Color Input on Substrate slab
Connect Substrate Slap output pin to Front Material

Expected Result

The pixel normals in base color should be affected by connected normal map

Observed Result

The pixel normals in base color only display effect of vertex normals

Affects Versions

5.8

Platform(s)

Windows

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