Ok, after searching within this forum and making some new tries, it seems to be a bug.
On this forum, I found some topic where other users indicated that cue point seems to not be used correctly (see here) even if it’s a one-year-old topic, and Torben confirmed that markers could be applied if data are available in MMD file or in database (see here and here).
Now, I don’t use MMD files in my configuration : all cue points are set in database.
But previously, I had some MMD files in a folder, created at the beginning of my mairlist configuration. And I forgot that they were there.
Recently, I turn off an option regarding MMD files (as I don’t use them anymore) and where I didn’t think about the relation with the hook container.
Indeed, when I set this option back on :
…cue points are now correctly used by the automatic hook container.
I don’t understand the link between the “default task for new files” and the “automatic hook container”. But I can tell that turning on this “read MMD file” make the cue points correctly used and this, even if the “look up file in databases” (I guess this option is the one that should be used …) had always be checked…
Maybe I’m wrong, or maybe it’s a bug.
For now, I will generated a whole set of MMD files in order to make the automatic hook container working (but not the very best solution) 
.