For anyone coming across this and seeing 'selectedItems' forever an empty array, I found this to be the case. The solution I found was to put my calcite-dropdown-items in a calcite-dropdown-group. Nothing else needed beyond that. This was the only way I found to know when/which item is selected in a calcite dropdown.
(@JohnGrayson howdy, been awhile!)
CORY EICHER
www.eichcorp.com
cory@eichcorp.com