Material Layer Functions always Recompile?

Development Rendering
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1

I’ve notice that in 4.27.2 Layered Materials always recompile everytime I open the Engine and then an actor using that material spawns for the first time, it also happens when open the Material Instance or the Material Layer function.

It doesn’t matter if you let the material to fully compile, if you close the engine and then open again, the shader will compile again as it wasn’t previously compile, that is not the behavior we can see on non Layered Materials.

So, why is this happening? and is anything that can be done to prevent this to happen?

MasterBaseInstance
MasterBaseInstance1918×776 159 KB

MasterBaseMaterial
MasterBaseMaterial1220×358 82.9 KB

MaterialLayerBlend
MaterialLayerBlend1069×651 82.7 KB

MaterialLayerBronze
MaterialLayerBronze1583×836 137 KB

MaterialLayerChrome
MaterialLayerChrome1510×846 309 KB

Attached a very simple example that also cause the issue.

2

Even closing and open a Material Layer Function cause Missing Cached Shader Maps (without exit and open the Editor).

LogMaterial: Display: Missing cached shadermap for Material_4 in PCD3D_SM5, Default, SM5 (DDC key hash: EBE98A0FC8F7B91E741745C23A9E43A6ADEE52FE), compiling. 
LogMaterial: Display: Missing cached shadermap for PreviewMaterial_1 in PCD3D_SM5, Default, SM5 (DDC key hash: 6B89AE8F455A2F6B38CF9D79712DA187F5C1C8AB), compiling. 
LogMaterial: Display: Missing cached shadermap for Material_4 in PCD3D_SM5, Default, SM5 (DDC key hash: 3BC43DADFC3BB8C18686DC837B7FFDB695256A6F), compiling. 
LogMaterial: Display: Missing cached shadermap for PreviewMaterial_1 in PCD3D_SM5, Default, SM5 (DDC key hash: 672F27375C923AB703DA64B4696F895520E259F4), compiling. 
LogMaterial: Display: Missing cached shadermap for Material_4 in PCD3D_SM5, Default, SM5 (DDC key hash: 4C547AD661665382C85BFEAEEC1477C60711CC80), compiling. 
LogMaterial: Display: Missing cached shadermap for FMatExpressionPreview MaterialExpressionMaterialLayerOutput_0 in PCD3D_SM5, Default, SM5 (DDC key hash: DD030A8B6E29035279EB8AD260223E258C69DAFA), compiling. 
LogMaterial: Display: Missing cached shadermap for FMatExpressionPreview MaterialExpressionVectorParameter_0 in PCD3D_SM5, Default, SM5 (DDC key hash: C18C04965FE905AB72AB82AEE6D514AC6C7374D4), compiling. 
LogMaterial: Display: Missing cached shadermap for FMatExpressionPreview MaterialExpressionTextureSampleParameter2D_0 in PCD3D_SM5, Default, SM5 (DDC key hash: 192465D51C69E16F2D05858A2D7AF38050FFA064), compiling.