Changing lighting in ARCore game

So I’m making an AR game and I started from unity’s official ARCore example (placing Andy the android on planes), and just modified it a bit. I have a screenspace camera canvas , which should always be lit up only with directional light. The objects in canvas are in a different layer, seen by a different camera. I put a directional light with culling mask for that layer, and removed that layer from the enviromental light which came with the example scene, but the lighting on that canvas still changes depending on camera’s environment darkness (like it’s lit up with the enviromental light). Shouldn’t the directional light’s culling mask turn off the enviromental light for the canvas? Any idea how to solve this?