Calculating a field to be equal to the 'created_date' field, and then creating a view of the hosted feature layer causes the view's number of records to increase drastically in Portal for ArcGIS.
This defect was logged against a version of the software no longer supported. The issue is not reproducible in newer versions of ArcGIS Enterprise. If the issue persists, contact Esri Support Services as a new reproduction case is needed to continue investigation.