Picture above is emacs 26.2, it is ok. I can't figure out why emacs 26.3 and 27.0.50 are not ok with the same config of emacs 26.2. Maybe I should trye to compile emacs from source. I use emacs on linux by compiling from trunk. But I don't set up develop environment on windows. 
------------------ 原始邮件 ------------------
发件人: "Juanma Barranquero"<lekktu@gmail.com>;
发送时间: 2019年9月25日(星期三) 晚上11:22
收件人: "Eli Zaretskii"<eliz@gnu.org>;
抄送: "Albert"<georgealbert@qq.com>;"37495"<37495@debbugs.gnu.org>;
主题: Re: bug#37495: 27.0.50; lwindow doesn't pass to system



On Wed, Sep 25, 2019 at 5:14 PM Eli Zaretskii <eliz@gnu.org> wrote:

> I see the same, FWIW, and the *Help* window pops up before I hit 'r',
> just after I hit lwindow.
>
> I think this is normal.

Yes, it is normal. But it's not what happens to Albert.

So I think you're right, something in his system's set up is messing with keyboard handling, and it's not an Emacs thing.

But somehow it didn't affect 26.2... Weird.