Just updated to version 137, and noticed that when I open a menu from the main menu bar, the ampersands briefly show before being replaced and formatted (see screenshot).
After a few seconds they change, however they appear every time I return to a menu item.
I have tried using atom --safe and I get the same behaviour.
Atom version 0.137.0 (chocolatey), Windows 8.1, x64.
An issue is logged in Github for this: