I have come across an issue when using the search widget with a vector base map. For some reason when zooming to the result in my case a polygon the highlight graphic doesn't show up. This is even the case in the search multiple sources example in the 3.x api samples. Open the sample in sandbox then switch base map to "topo-vector" then search using any source that isn't the geocoder and the result graphic doesn't display. Is this a known issue? Just to clarify I am using the 3.x api at the moment.