When adding data via the new WAB 2.4 Add Data widget, I'm getting zoomed to the wrong extent, not the extent of the data. The data is added successfully, and it is present in the layer list, and when you zoom to it from the table of contents, it shows up in the right place on the map, but the initial zoom to does not work.
Shot in the dark here - reduce your dataset you are uploading to one or two records that you absolutely know have correct coordinates, with as few fields as possible, Load that, see if it works. I had a similar issue occur in the 2.3 version of the geoprocessing widget, and I found that it was an error with the data going into the app that was causing the widget to perform oddly.