[Solved] Slide only on one note possible

I have again a strange behavior when I want to put a slide property for 2 notes.
They are on the same voice (1 stem upward).

One note is working fine, the other note doesn’t display the slide.

You can see this here: https://drive.google.com/file/d/1NWKrBkpjG1wO3M_HJ_qX9fXcTuU-6mZC/view?usp=sharing

If I make a new project with just these 4 notes it is working.
So somewhere in the project this behavior is created…

Attached is a minimal project.

Edit: [Solved]
The note before didn’t have a string indication so the slide could not work.
Slide.dorico.zip (791 KB)