Menu-bar flickering on Win10

[Arash Esbati]

Hi all,

I had a minute and gave Eglot for a LaTeX file a roll.  Digestif as
server doesn't work on Win10, so I installed texlab which works.  For
the good news, I added one entry to `eglot-server-programs' and 'M-x
eglot RET' just worked.

For the bad news, I observed a random flickering in the menu-bar when
completion happens which looks like this:

This is with 'emacs -Q' and 'Corfu' providing the pop-ups.  Is this a
known issue with child frames?  I'm asking if it's worth filing a bug
report.

Best, Arash