Shortcodes are not working in page templates

I downloaded WordPress 5.9-RC1 to try the new full site editor using the “WordPress Beta Tester” plugin, and while I was testing it, I noticed that the shortcode block does not transform the shortcodes in the page template. (Works fine in the actual page/post content.)

I created a new plugin and I added the following testing code to it:

add_shortcode('note', 'tt_test_note');
function tt_test_note($atts, $content = null) {
    ob_start();
    ?>
    <div class="note" style="margin: 30px 0; padding: 27px 40px; background: #fcf3dc; border-radius: 5px;">
        <p><?php echo $content; ?></p>
    </div>
    <?php
    return ob_get_clean();
}

<h2>Environment:</h2>
1. WordPress 5.9-RC1
2. Active theme: Twenty Twenty-Two Version: 1.0
3. Active plugins: only the shortcode plugin that has the code above and nothing else
4. PHP: 7.2.34-28+ubuntu18.04.1+deb.sury.org+1

<h2>What’s the issue?</h2>
When using the shortcode [note]test[/note] in Gutenberg’s own shortcode module works in the actual page, but not in the template editor.

<h2>How to reproduce the problem?</h2>

1. Create a new plugin and add the code mentioned above
2. Go to Appearance > Editor
3. Click on the WordPress icon at the left site
4. Select Templates > Page
5. Add a new shortcode block above Post title (https://imgur.com/5lFPgtE)
6. Write this code there: [note]test[/note]
7. Save the template
8. Create a new page
9. Add a new shortcode block and write the same shortcode there (https://imgur.com/5lFPgtE)
10. Save the page and check it

You’ll see the [note]test[/note] code is displayed above the post title, but the yellow block shows correctly up below.

View post on imgur.com

<h5>Note</h5>
The same shortcode works if I place it into the “Header” or “Footer” part.

View post on imgur.com

View post on imgur.com

Playing around with it more, it seems the shortcode starts working after I create a template part from the whole section. Still weird that it does not work by default.