Is it normal that aria-live (polite) doesn't work on table caption in Safari?

Question

If I place the aria-live attribute in a table caption like this:

    <table>
        <caption aria-live="polite"></caption>
        ...
    </table>

And then update the caption's textContent VoiceOver (macOS) in Safari (14.0.3) doesn't read the caption. It works with VoiceOver in Chrome. I also tried to put a span inside the caption and many many variations on this theme (moving the aria-live attribute, updating the innerHTML, etc.). But the moment the change is inside the caption, Safari will not read the change.

Is anyone have an idea how to make this works?

Here's a fiddle that demonstrate the problem: https://jsfiddle.net/06phkrL8/