I have a question about the 'Use symbols defined by the layer' option in the Query widget.
In our scenario, we have a layer (1) hosted in ArcGIS Online. This layer has been copied and saved 3 times with different filters and symbology applied (2). Three Web AppBuilder apps have been created from each layer so we have a different view as required by end users. This is our process because if any updates are required, they can be applied to 1 layer and then are filtered into the 3 apps.
With the Query widget, i built some queries and selected the option 'Use symbols defined by the layer'. When I run the queries, the symbology of the original layer (1) is applied to the results, instead of the symbology that was saved with the copy (2).
The same thing happens if I add a layer (original, not a copy) to a web map, change the default symbology (don't Save Layer), save the map, create a Web AppBuilder app, add the query widget, and define 'Use symbols defined by the layer'.
A workaround could be to use 'Set custom symbol' and match it to the desired symbology but this would only be suitable for layers symbolised by a single symbol.
I can understand why the original symbology would be applied to the results, but what if you don't want the symbology for a layer in a web map to be the default symboloyg?
The "Use symbols defined by the layer" means that the results of the query will be drawn using the symbol defined By ArcGIS Server for that layer (not the web maps). If you want to have symbology that is different from the symbology defined by the ArcGIS Server map service then your option is to use the "Set Custom Symbol", which is a single symbol as you already know. Your other course of action would be to publish another map service using the same data but with different symbology.