There are two shader stores in this project. Could be the way vite is optimizing the babylonjs/core package, because it is spread across two projects. I assume that if you move the code from the 2nd project directly into the main project, or have a single project with everything babylon-related, it will work as expected.
In general, the problem is that the shader is loaded to one shader store, but when rendered, there is a different shader store that is being used to load the shaders from. Didn’t dive too deep into why it is happening, mainly because I had to debug the production code, and it is not very simple 