On Sat, 26 Oct 2024 at 18:40, martin rudalics <rudalics@gmx.at> wrote:

> Having done this, I can see the output in journalctl.
>
> Using xwininfo, I found that the first window is ID 0x5000148 and the
> second window I opened is ID 0x500031c.

Just to make sure: The first window is the initial window Emacs made
with normal size and the second window the one you make via C-x 5 2 with
the menu bar still enabled and the abnormal size. Correct?

Correct, except that I was working with the menu bar disabled. Do let me know if you'd like me to redo with the default menu bar setting, before I reply to the rest of your questions, and apologies if this confused things.