This is most likely due to native compilation which compiles the
unquoted lambda. Once compiled, it (presumably) fails to be passed to
the external emacs process.

Ah, interesting.  Is this a bug or a feature?

I think the bug's with org-mode. As I explain elsewhere in the thread,
this lambda is to be treated as data, and written to a file to be
executed by the external emacs instance. It should always have been
quoted (naming it happens to work also).

Regards,

-- 
Sébastien Miquel