ArcGIS Online does not allow sorting of members based on the 'Available credits' column.
Last Published: January 29, 2016ArcGIS Online
Bug ID Number
January 19, 2016
August 21, 2020
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 as designed. Users are not allowed to sort on the 'Available credits' column.