[Solved] Inline comment small comment icon not displayed

Hi, this topic is the same as already posted here, on the WP support section.

I’ve been using inline comments successfully in some posts for a while but since I changed theme to a new one, inline comment seems not be working fine anymore, although it’s been working once!…

So here’s what I do under the classic editor :

1. select text,
2. click in the wpDiscuz icon and enter a question.
3. Then I can see in the post something like:
   

   [wpdiscuz-feedback id="vca2ffiw68" question="What do you thing about it?" opened="0"]aren't books of photographs "mausoleums of images"?[/wpdiscuz-feedback]

I’d expect to find a “small comment icon” next to this text in the published post, as it was the case before.
But nothing. At all. And the HTML shows nothing related to feedback/in line comment.

I wrote it happened once, and it may be seen here.

Here is a video to show what I'm trying to explain.

What I don’t understand is why the 1st inline comment is taken and not the 2nd one.
On a next post on this site, I tried to insert just one inline comment shortcode, but no icon is displayed in the published post.