By default the maximum number of lights per material is 4.
You may change it with
material.maxSimultaneousLights = your_number
Example - https://playground.babylonjs.com/#20OAV9#5972
Also there a way to control which meshes will be lit. A mesh can be added to the excludedMeshes array or add the ones not to be excluded to the includedOnlyMeshes array.
Example - https://playground.babylonjs.com/#20OAV9#8
thank you for your reply, i will try it.