I have an issue with casting shadows from multiple objects, I’m very new to Babylon and webGL in general so please forgive me if this is a well-known issue. For the same reason, I’m also unsure how to properly describe the issue but it’s very obvious in the playground I created: https://playground.babylonjs.com/#5TBR1E#4
In my use case, the items will not be animated but it helps to visualize the issue.
Added sphere to visualize the light position - https://playground.babylonjs.com/#5TBR1E#5
I see no problems here - when meshes are lit they have shadows, if they are unlit - no shadows The Directional light is emitted from light source in the specified direction, as in your case.
Maybe you would change directional light to Pointlight? https://playground.babylonjs.com/#5TBR1E#6