Chrome does not expire cookie at Max-Age

The following code, when run in Chrome/Chromium, keeps outputting <i> 'testme=Banana' indefinitely:

document.cookie = "testme=Banana; Max-Age=4";
let i = 0
setInterval(() => {
  i++
  console.log(i, document.cookie)
}, 1000)

In Firefox, it starts outputting empty string from i=4 (as one would expect).

What’s the deal with Chrome? Is it a bug?

UPDATE: Looks like this is the bug reported here.