Ghost instrument name cannot be removed

Hi everyone,

I'm using the appimage release of 4.0.0 on ubuntu, and I met the following problem:
I'm trying to add text at the end of the score, on a dedicated page, so I'm appending an horizontal frame after the last measure.
The problem is an instrument name appearing on the new page, even if there is no staff (see: https://musescore.org/sites/musescore.org/files/2022-12/example_3.png).
I have no way to get rid of it, since there is no option to remove it individually (if I try to delete it, it deletes every occurrence of it across the score, which is not what I want).

Is it a bug? Is there some workaround?

Edit: The incriminated score: https://musescore.org/sites/musescore.org/files/2022-12/Veni%2C%20veni%…
Edit #2: This problem doesn't seem to affect text or vertical frames, only horizontal frames.
It means that adding text at the end of a score can be done without any trouble with a text frame.
However, what I'm actually trying to do is to add a two column text, like this:
https://musescore.org/sites/musescore.org/files/2022-12/example2.png (without the abbreviated instruments name, of course),
which seems to be only possible with horizontal frames.
Edit #3: Well, I managed to do it with a vertical frame, it wasn't very instinctive though. Anyway, it would be surprising if the behaviour I described was intentional.