I’ve encountered the same problem. The reflections or reflective surfaces become translucent from certain views. There’s edge artifacts too. Is the scene using Screen Space Reflections? I had the translucency, or perhaps it’s colors bleeding onto / through meshes and materials from surroundings in that scene, in the material editor preview. When I increased Roughness from 0 to 0.1 or higher, the translucency disappeared and it was back to an opaque surface, which is how I had it set. After applying and saving the material, the translucency didn’t occur in the scene when placing the material on an object.
The other artifacts on / around edges of meshes I’ve seen in a blank template scene with and without changing settings for lighting, RT on/off, and haven’t figured out how to get rid of it yet.