This happened to me as well, but with registered feature services. The attribute rules had already been working previously. Working with ESRI, we had to change the expression so that it didn't directly reference the Shape.STArea() field because it changes to Shape__Area when it is published. This started happening after applying the Portal for ArcGIS Security Update 2023. So for instance, the rule went from "Round($feature['Shape.STArea()']/9, 2)" to now "Round(Area($feature,'acres'), 2)".