When adding time-enabled data to ArcGIS Enterprise Portal Map Viewer and using the time slider to display data by date in intervals, the time slider queries all records at once and displays only relevant data for each desired time, resulting in data displayed to flash for each increment.
This defect is logged against a version of the software which is no longer supported. The issue is not reproducible in newer versions of ArcGIS Enterprise Map Viewer (ArcGIS Maps SDK for JavaScript 4.x). Map Viewer Classic (ArcGIS API 3.x for JavaScript) is now deprecated (see deprecation notice https://support.esri.com/en-us/knowledge-base/deprecation-map-viewer-classic-deprecation-000030662 ). It is recommended to use Map Viewer for all workflows.