This is not reproducible with ArcGIS Enterprise 10.7.1 and ArcGIS Enterprise 11.0 print services (published from ArcGIS Pro). We highly recommend moving to print services published from ArcGIS Pro.
https://enterprise.arcgis.com/en/server/latest/publish-services/windows/tutorial-publish-additional-layouts-for-printing-with-arcgis-pro.htm