Emacs 26.2/26.3/27.0.50 are downloaded from gnu website(http://ftp.gnu.org/gnu/emacs/windows/emacs-26/ and http://alpha.gnu.org/gnu/emacs/pretest/windows/emacs-27/).
I tried to comment code in w32fns.c to bypass lwindow to system, but failed without luck.
------------------ ???????? ------------------
??????: "Eli Zaretskii"<eliz@gnu.org>;
????????: 2019??9??26??(??????) ????8:17
??????: "Juanma Barranquero"<lekktu@gmail.com>;
????: "Albert"<georgealbert@qq.com>;"37495"<37495@debbugs.gnu.org>;
????: Re: bug#37495: ?????? bug#37495: 27.0.50; lwindow doesn't pass to system
> From: Juanma Barranquero <lekktu@gmail.com>
> Date: Thu, 26 Sep 2019 13:45:03 +0200
> Cc: Eli Zaretskii <eliz@gnu.org>, 37495 <37495@debbugs.gnu.org>
>
> Why it didn't happen with 26.2, I have no idea.
Maybe Emacs 26.2 was downloaded from a different site, or it was a
different build?