emacsclient --create-frame not creating a window frame

[Luca Ferrari]

Hi all,
I've emacs 29.2 on ubuntu 24.10, and I'm experiencing some problems
never encountered.
First of all, I compiled emacs from sources.

I launch the emacs daemon via a systemctl script:

[Service]
Type=forking
ExecStart=/opt/emacs/emacs29.2/bin/emacs --daemon

So far so good, in the terminal, if I exec emacsclient the client is
launched in text mode.
But then, if I launch emacsclient --create-frame the client still runs
in text mode, so there is no chance to get a window frame.

Not being able to see any error on the console, how can I investigate
the problem?

Thanks,
Luca