I’m guessing it’s in the material; maybe a setting in the material details panel. One thing to check is if “High Quality Reflections” is enabled in the material. It’s located a bit far down the details panel when in the material editor for the material on the silver bar. Something isn’t configured correctly for the mesh / material. It’s not going to fix it by changing RT samples per pixel or bounces, or SSR settings. It could also be conflicting reflections methods (such as RT overlapping the nearby reflection capture probe or box), or the nearby reflection capture probe is not completely surrounding the mesh but intersecting it somehow. Try watching the learning video on reflections in the scene, and reading the doc page for enviro reflections. I recall there being info / tips regarding how to set captures and settings so it doesn’t cause flickering or black areas.