> I cannot reproduce on stable branch either. Only on main.

Then why do you think this is a problem in the core?

As I said in my first message, I either misunderstand something about autoload or it is some kind of

Emacs bug.

Note that doing emacs -Q -l /tmp/bug.el vs emacs -Q /tmp/bug.el + eval-buffer yields different results.

I cannot possibly see how it can be anything to do with Org and I have no clue how to approach debugging this.

Best,

Ihor