Unable to setKeySelected on Selection Within Hook

[NetrixDES]

Looking for some assistance figuring out what might be going wrong with the following attempt at selecting a DetailsList row programmatically within a hook (see below). Unfortunately, while I've found a number of similar issues (with solutions) on both Stack Overflow & the "Issues" tab here, I have yet to find any that have helped me to understand what I may be doing wrong in my implementation.

CodePen
Stack Overflow Post

Code (please review "// Proof #" comments for potential key areas where my logic/understanding may be off):

const {
  ICommandBarItemProps,
  CommandBar,
  Check,
  MarqueeSelection,
  ISelection,
  Selection,
  SelectionMode,
  SelectionZone,
  IRawStyle,
  mergeStyleSets,
  ThemeProvider,
  initializeIcons,
  DetailsList
} = window.FluentUIReact;
const { IExampleItem, createListItems } = window.FluentUIExampleData;
const { useConst, useForceUpdate } = window.FluentUIReactHooks;
initializeIcons();

const SelectionBasicExample: React.FunctionComponent = () => {
  const items = useConst<IExampleItem[]>(() => createListItems(10));
  const [selectedItems, setSelectedItems] = React.useState<IExampleItem[]>([]);

  const getCurrentSelection = () => {
    console.log(`getCurrentSelection: ${JSON.stringify(selectedItems)}`);
    let newSelection = new Selection({
      selectionMode: SelectionMode.multiple,
      items
    });

    // Proof 1 (builds on Proof 3 below) - the items.forEach() logic updates the selection:
    newSelection.setKeySelected(items[0].key, true, true);

    console.group("items.forEach");
    items.forEach((i) => {
      console.log(i.key);
      console.log(selectedItems.some((si) => si.key === i.key)); // Proof 2 - row 5 SHOULD be getting selected when the button is clicked
      newSelection.setKeySelected(
        i.key,
        selectedItems.some((si) => si.key === i.key),
        true
      );
    });
    console.groupEnd();

    // Proof 3 - selection.setKeySelected() works:
    newSelection.setKeySelected(items[9].key, true, true);
    return newSelection;
  };

  const [selection, setSelection] = React.useState(getCurrentSelection);
  React.useEffect(() => {
    console.log(`useEffect: ${JSON.stringify(selectedItems)}`);
    setSelection(getCurrentSelection);
  }, [selectedItems]);

  const detailsList = React.useMemo(() => {
    console.log(`detailsList: ${JSON.stringify(selection.getSelection())}`); // Proof 4 - After the button is clicked, the selection should include row 5
    return (
      <DetailsList
        items={items}
        selection={selection}
        selectionPreservedOnEmptyClick={true}
      />
    );
  }, [selection]);

  console.log("rendering"); // Proof 5 - Final render occurs after all actions relating to the selection of row 5 have completed

  return (
    <div>
      {detailsList}
      <p>{JSON.stringify(selection.getSelection().map((s) => s.key))}</p>
      <button onClick={() => setSelectedItems([items[4]])}>Select Row 5</button>
    </div>
  );
};

const SelectionBasicExampleWrapper = () => (
  <ThemeProvider>
    <SelectionBasicExample />
  </ThemeProvider>
);
ReactDOM.render(
  <SelectionBasicExampleWrapper />,
  document.getElementById("content")
);