Interactive Legend isn't interactive when using an Arcade expression with unique symbol style.

[BlakeTerhune]

When creating an Interactive Legend Instant App, the interactive legend isn't enabled when the layer in the web map is styled as unique symbol with an Arcade expression. Even something simple like this (giving true or false in the legend) drops the "interactivity" of the legend in the app.

IsEmpty($feature["Some_Field"])

Is this a bug or am I doing something wrong?

Edit: This is on ArcGIS Enterprise 11.0

[BethRomero · Accepted solution]

Unfortunately, at this time symbology styled with an arcade expression is not currently supported in the Interactive Legend.  

[BlakeTerhune]

Thank you for confirming. Would it be appropriate to request this feature in ArcGIS Ideas?

[BethRomero]

Yes, that's a great spot to document the request.