Feature pop-ups lack attribute information in Portal for ArcGIS web applications if the corresponding service is published to a non-federated ArcGIS Server that shares the same host name as the Portal for ArcGIS site.
This issue is not reproducible on current releases of ArcGIS Enterprise. Contact Esri Technical Support to open a new bug if a similar problem is encountered on ArcGIS Enterprise 10.7 and the higher version.
解决办法
Add services from an ArcGIS Server site that does not share the same host name as the Portal for ArcGIS site or federate the ArcGIS Server site that shares the same host name with the Portal for ArcGIS site.