[4.24.3] Why do shaders recompile every time material window is opened?

Development Rendering
, , , ,
1

Using a custom-built (Oculus branch) engine - version 4.24.3.

Every time I open a material window, the material’s shaders are recompiled due to ‘missing cached shader map’ for FMatExpressionPreview nodes. Not only that, every time the window is opened, the count of shaders to be recompiled increases.

https://i.ibb.co/pf3CnvQ/Shaders-Recompiling.png

In the log I see:

https://i.ibb.co/87VXcpj/Shaders-Recompiling-Log.png

I’ve tried re-filling the local DDC, which finished after an overnight rebuild of the DDC, however the issue still persists.

Is this a known issue with 4.24, or is there a workaround?

[Edit] The same thing happens if I wait for all shaders to be finished compiling - on opening the material window it recompiles again.