When using the Shape.Area field in label expressions or where-clause, labels are not displayed in a map service published from ArcGIS Pro.

Workaround

1. In the arcgisinput-directory of the service (...\arcgisserver\directories\arcgissystem\arcgisinput\<ServiceName>.MapServer\extracted\p20), open the *.msd file using a zip-tool, and navigate to the map-folder.
2. Unzip the appropriate <layer_name>.XML, and modify the label expression.
3. Add it back to the *.msd file by overwriting the existing XML.

Steps to Reproduce