I am using Emacs 29.1 downloaded from
https://ftp.gnu.org/gnu/emacs/windows/emacs-29/emacs-29.1_2.zip on Windows 10.
Every now and then, without any discernible pattern, Emacs in GUI mode doubles its main menu entries. With main menu I mean
File / Edit / Options / Tools / Text / Help
becomes
File / Edit / Options / Tools / Text / Help / File / Edit / Options / Tools / Text / Help
This is also true when another mode is active which adds top level menu entries.
When clicking on such a doubled menu entry, the menu entries get redisplayed and I am clicking into empty space - no error message.
Sure I wanted to take a snapshot but sending Emacs to the background and bringing it to the front caused a re-display and now I can't take the screenshot exhibiting the problem..
A cosmetical problem as no other harm is done.
I have witnessed that behaviour for years on Windows builts.