I can confirm that in UE5.02 in vulkan mode nanite works.
Create a third person project. search for RHI and set it to vulkan.
Enable nanite for the objects in the scene (you do that in the content browser)
Switch the viewport mode to nanite. everything works.
Warning it takes like forever because the editor will calculate a bunch of shaders every time you do the steps above.
I suggest leaving it be to finish the shader compilation each time. So switch to vulkan restart, leave the editor do its thing.
then enable nanite for the ramp, cylinder and whatever in the LevelPrototyping folder. (leave the chamfer cube alone)
editor will recompile shaders, leave it be.
After that it works