org-babal-lilypond fontification error

[Jonas Damm]

Hi,
I am using org-babel to create music sheets with lilypond.
For some reason the fontification is not working anymore:

Example:

#+begin_src lilypond

  \relative c' {
    c d e f g
    }

#+end_src

The syntax highlighting breaks when entering the "{". The error is:

Org mode fontification error in #<buffer dreiklang_improvisation.org> at 80
(80 is the line with #+end_src)

GNU Emacs 29.0.90 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.37, cairo 
version 1.16.0) of 2023-04-26
Org mode version 9.6.4 (release_9.6.4-9-g8eb209 @ 
/usr/local/share/emacs/29.0.90/lisp/org/)
GNU LilyPond 2.24.1 (running Guile 2.2)

Thanks for any help.
Regards,
Jonas