I have a simple polygon feature class with one Area field (Double). I have added an Arcade Attribute Rule to calculate area when creating and updating.
Round (Area($feature, 'Acre'),1)
There is no error message when adding the rule, however when I go to create the polygon I see the field area is not populated with acres.
What am I missing?
Your Arcade expression is correct, so iI don't think you should change anything here (I tested it using the Attribute Rule Calculation profile in the playground and of ArcGIS Arcade | ArcGIS for Developers and using 10 decimals to see something):
Do you have a screen grab of how you configured the Attribute Rule?
I don't see anything strange in your screenshot of the tool. Be sure to revise all the requirements here: Add Attribute Rule—Data Management toolbox | ArcGIS Desktop and if the problem continues please contact your local support to walk through the problem.
After your suggestion, I revised the whole thing again and now it work in ArcGIS Pro. However, the Rules do not get populated in the web map nor do the features I create in the web map transfer to the enterprise data. Did I do something wrong while servicing?