I see that the Feature Set option is set to Supported, so you won’t get true micro-polygon displacement. Perhaps your material is set to use Displacement Only in its settings. Try changing the Displacement method to Bump Only, OR, if you want true displacement, change the Feature Set to Experimental, add high subdivision or adaptive subdivision to the object, check that the material settings are set to use Displacement Only or Displacement and Bump, and try a render.
