PROBLEM
When adding a hosted feature layer with graduated symbology from ArcGIS Online in ArcMap, the graduated symbology is not retained.
This is a known limitation. In ArcMap, if a feature layer is exported from ArcGIS Online, it is unable to render graduated symbology. Refer to ArcMap: 00085 - Layer uses an unsupported renderer for more information.
As an alternative, import the hosted feature layer in ArcGIS Pro using the instructions provided below.
Article ID: 000022932
Get help from ArcGIS experts
Download the Esri Support App