There is a bug (BUG-000169410) filed that says:
| The "No Data" error message is returned using a referenced service from ArcGIS Server 10.81 in a serial chart element when 'Split by field' is defined in ArcGIS Dashboards. |
Is there any update on this? This issue occured during the last AGOL update so several of my dashboards and charts have been broken since early June. This really needs to be fixed. I am looking for someone from ESRI to respond.