So i kind of debug ESRI js api code and saw that the param maxAllowableOffset do all the damage inside the file Search.js
The value of maxAllowableOffset was 'n' so i changed it to be 0, and only then it zoomed correctly
I've download the JS API to our IIS server and modify the Search.js [The path is [SERVER_NAME]\js_api\3.18\esri\dijit\]
file now look like this
It worked for us.
hope it will help you as well.
I sort of ran into similar problem. My layer was published with Feature access capabilities. The feature layer's projection was off slightly compared to the default mapping layer although they used same mxd's and had same projection. I was going to try Shahar's solution, but found out an easier way to suit my needs. So the simple solution that worked for me was to publish the mxd as mapping(default) and WFS enabled instead of mapping and Feature access. The search widget will work with the layer.