A map or feature service with a relationship class where multiple layers are based on the same feature class only displays related field values in the pop-up on the first layer from the same feature class.
Last Published: November 9, 2015ArcGIS Online
Bug ID Number
July 14, 2015
May 31, 2023
After review by the development team, it has been determined that this issue is related to a known limitation with the software that lies outside of Esri's control. The issue's Additional Information section may contain further explanation.
This is known for know. Will be fixed in upcoming release.