Problems with using "Set Rive Descriptor" in Unreal Engine integration

I'm doing this (see screenshot below) in Unreal to dynamically swap artboards at runtime (I'm really hoping data binding will simplify this). Is this a valid approach?

It works fine in the (unreal) editor, but doesn't work in a packaged build. It seems like Unreal doesn't have a reference to the rive file with this method.

The logs in my packaged build show the following:

LogScript: Warning: Accessed None trying to read property RV_TrbMain_Artboard
LogRive: Warning: Could not initialize the artboard by the name 'Soul_Default'.