Custom Attribute values are not appearing in the DX NetOps Performance Management Performance Center web UI.
The Custom Attributes themselves are present, but they have no values.
The values set are present in Odata exports.
Something unable to be determined caused the Custom Attribute values to not be synchronized to Performance Center.
All supported DX NetOps Performance Management releases
Running a Full Synchronization of the Data Aggregator Data Source in Performance Center resolves the problem.
To run this go to Administration->Data Sources->Data Sources. Select the Data Aggregator Data Source. Select the Resync button. Select the Full Synchronization checkbox and run the synchronization.
NOTE: On Production systems the Full Synchronization of the Data Aggregator Data Source is recommended to be run after hours to limit possible impacts for users in the UI.