Multiple default audio players on one post don’t load

I’m an old blogger and WordPress user (started in 2003 with b2) and I wrote a few month ago a blog post with many default audio players. There are 60 audio (Gutenberg) blocks in this post, they’re all related to mp3 that were previously ulploaded in the Media Library.

example :

It was all working fine at the time I wrote the post (in Feb 2024). A few days ago, a reader wrote an email to me saying that some audio seemed to be missing. And indeed, I can’t seem to be able to play all of them. Some of them appear as “blank”, like if the mp3 was not “loading”.

I see the same behaviour in front and back-end. In edition mode on my post, I see also that some blocks are “blank”.

If a try just to edit them in HTML, and then click back to the visual editing, the mp3 can be played.

But this does not solve at all the playability of the audio blocks in the published posts, and there is no consistancy between the “blank” blocks on the published and the editor version of the post.

I tried to delete cache, deactivate cache for this page, and even CDN, but same behaviour.

Is it a bug or am I missing anything? ??

The page I need help with: [log in to see the link]