I've implemented some attribute rules for a feature class to calculate immediately on insert and update. I know the rules work because when I manually edit the table, or use arcpy.UpdateCursor() to iterate through the table, the rules are enforced. The problem comes when I try to use Calculate Field(s) geoprocessing tool I get an Error 999999 and an "Arcade error: Field not found" for a field that definitely exists. I've attached one of the rules and the error message. Notably there's no GlobalID listed in the error message despite the fact that all the features have a GlobalID.
Any thoughts why this happens? For now I'm just disabling attribute rules but I'd like to figure out what's happening. I'm using ArcGIS Pro 2.4.3.