A few of our ArcGIS Server map services draw very slowly, so we sometimes use cached map services in our out-of-the-box template applications. After intial release, it was pointed out very quickly that the feature does not get highlighted when the pop-up is opened in the ones with the cached services:

In WAB, the feature is highlighted:

Highlighting the feature can be very helpful when using auto-generated random colors (sometimes you get polygons with the same color next to each other) or when there are features from other layers that make it hard to discern polygon boundaries.
This is the URL to the map service:
https://map.opkansas.org/arcgis/rest/services/MapViewer_ExistingLandUse/MapServer