The interface Alias value, represented by the ifAlias MIB OID value for the interface, is not updated in the DX NetOps Performance Management Portal web UI.
In Inventory->Interfaces we see the old and wrong ifAlias value in the Alias column.
In the Interface Inventory List View for the device Context Report we see the wrong ifAlias value in the Alias column for the problem interface.
The Interface Metric Family is in a Monitoring Profile using Change Detection set at a 24 Hour Rate. It should be checking for Alias updates every 24 hours. The ifAlias was updated a long time ago.
All supported DX NetOps Performance Management releases
Unable to be determined before rediscovery resolved the problem.
Running a rediscovery against the problem device forced update to the interfaces Alias value using the new/current ifAlias value set.
Determining a cause would require debugging a live instance of the problem. There are a number of points in the path from device to tool that could result in possible failure. Once resolved it's often impossible to determine what had gone wrong.