Background of the Unexpected
As “sort of expected” (or not surprised), the New Map Viewer operates a little differently than the Classic Map Viewer.
Part way through working on an exercise, I discovered a potential snafu with Pop up Configuration functionality.
Searching for answers, I came across this AGOL Help link.
Map Viewer Web Map Compatibility
As one learns to expect (and amazed) when deeply involved in actual work that expected functionality is not working….in this case, the Configuration of Pop Ups.
Overview of Pop Up Configuration
Pop ups are configured in the “New” Map Viewer from the right side of the user interface. Seems easy enough. The key element is for the map designer to pay attention to which layer is being worked on (i.e. styled, configuration of pop ups, labels, etc).

By default, the Pop up appears with a title (usually from the first “text” field in the attribute table) and then a list of all of the attributes.
Remove Unwanted Fields from Pop Up
A typical workflow is to remove any data fields that don’t provide any meaning to the viewer (end-user) of the web map, especially those that only GIS nerds understand (e.g. unique IDs, shape, perimeter, area, length, especially when the units are non-familiar (e.g. sq. ft, sq meters, etc)).
The screenshots below show the list of fields in the default pop up. Use the Select fields to choose fields NOT to display (or re-display if they need to be viewed later).
Click Done when finished choosing or hiding fields to view in the pop up.


Change Field Alias Names
In addition, the “field name aliases” can be changed to make the context of the attribute field make more sense to the end user. In the “New” Map Viewer this is achieved by Configuring the fields, which is performed using the Configure Fields tool on the right side, just below the Configure Pop Ups tool.
The screenshot below shows the Configure Field tool showing a list of fields. Click on a field to view and change the Display Name. Click Done when finished configuring each desired field.

Arcade Expressions
Arcade expressions can be written and added to pop ups. Click the Manage expressions option to start creating an expression.

The expressions can be relatively simple or fairly complex.

The video below covers a couple of options to configure pop ups in the New Map Viewer. It also covers the possibility that one may need to Save the “New” Map and make a change in the Classic Map Viewer and saving the map before continue to configure pop ups in the “New” Map.