Is there a way to make it possible in the Select Widget to hold the SHIFT key on the keyboard and use the select tools in the widget (not the Map-embedded select tools) to add to the current selection? It does not appear to work for me inside the Select Widget itself and only seems to work with the map equivalent select tool. Likewise to be able to deselect part of the current selection using the CTRL key.
I have tried this in both our Enterprise environment (11.3) and ArcGIS Online and both yield the same undesirable outcome. See screenshot below highlighting the one that works and does not work for shift select.
