How do I run through all selected items in a ReferenceSetSelector in a microflow at a ChangeEvent?

On my referencesetselector i like to run a microflow on the Change Event. Inside the Arguments i can choose selection or all row.   The microflow creates 2 Parameter. If i try to loop trough my list the list is Always empty even i have selected one or more Elements.   The only way i fixed this is to create my own list from the upper object (board) but the i run for all items not only for the selection.   Any Ideas how to fix this.   Thanks Stephan