UE BP Tip - Materials Not Appearing On Instanced Meshes
This one catches me out all the time, Should be on by default but I guess there is hidden costs or a reason why it's not?
No materials appearing on Instanced meshes. The good news is you likely don't need to add more code to your BP, even though at this point you already have.
First make sure the static meshes being instanced have a material applied.
Next go into the material & tick the highlighted option "Used with instanced static meshes"
Now the materials appear on your Blueprints Instanced meshes.