Rendering Question

Hello to All!
Im having a render issue when using Rhino WIP7 for Mac. Im attempting to drawing a bathroom sink lighting installation and have every component on separate layers. However, when I try to give the bulbs (tubes in this drawing) their own separate material, the shelf changes too? Screenshot 2020-02-12 16.35.14.pdf (733.2 KB) Any ideas of what I might be doing wrong?
Thanks in advance for any helpJos bathroom Asteras.3dm|attachment (8.0 MB)