Possible bug in windowToggle when closingSelector returns EMPTY?

[d-bassarab]

Run example from https://rxjs.dev/api/operators/windowToggle:

const clicks = fromEvent(document, 'click');
const openings = interval(1000);
const result = clicks.pipe(
  windowToggle(openings, i => i % 2 ? interval(500) : EMPTY),
  mergeAll()
);
result.subscribe(x => console.log(x));

The observed output does not match example description: "Every other second, emit the click events from the next 500ms". The console keeps reporting pointer events even while the window is closed, i % 2 is falsy and EMPTY is returned.

To investigate I rewrote the code to use longer intervals and replaced EMPTY with of(0).

const clicks = fromEvent(document, 'click');
const openings = interval(2000);
const result = clicks.pipe(
  windowToggle(openings, i => {
    console.log(i % 2 ? 'open' : 'closed');
    return i % 2 ? interval(1000) : of(0);
  }),
  mergeAll()
);
result.subscribe(x => console.log(x));

The output while constantly clicking on the document is as expected:

closed
open
PointerEvent
PointerEvent
PointerEvent
closed
open
PointerEvent
PointerEvent
PointerEvent
closed
...

Shouldn't EMPTY behave exactly as of(0), completing right away and thereby closing the window?