A field name can be defined by an alias so that the field appears in the Feature Class Properties table with a name that is easily recognizable. In some instances, when changing the field alias of a feature layer in ArcGIS Pro, the change is not reflected when opened in ArcMap.
ArcGIS Pro does not preserve the change in field alias when changing from the field design, as this changes the properties of the feature layer that is added to the map. The properties are lost when the map is removed and added to ArcMap.
To preserve the field alias name change permanently, modify the properties of the feature class through Catalog in ArcMap, and open the data in ArcGIS Pro. Below are the steps to change the field alias name in Catalog.
Note: To check the changes made for the desired feature class, drag the feature layer into the map frame. Select the Identify tool from the toolbar and click the feature. Note the changes made to the alias name in the Identify tool pop-up.