In ArcGIS Web AppBuilder, the symbology for points changes the selected colors when a Group Filter widget is configured to select a point from data with date and time.
This issue is not reproducible in ArcGIS Web AppBuilder. If the issue persists, contact Esri Support Services as a new reproduction case is needed to continue the investigation. Check the "Append any/all expressions to existing map filter" check box in the Group Filter widget configuration window.