Yes, as shown in your screenshot with Nanite disabled, the water reservoir appears completely broken, now displaying Nanite’s fallback mesh.
It’s odd to see this mix of Nanite and regular meshes, especially with Nanite enabled on so few elements the benefit is really not worthwhile. It’s also strange that Bloober uses few or no LODs even on the regular meshes.
Also, using Lumen on regular meshes without LODs is likely quite costly in terms of caching.