Steps to reproduce:
# Create a 2D/3D URP project (or an empty project and import URP into it);
# Go to the "Project" window
# Right mouse click -> Create
# Find "Rendering" (or any other menu, which has submenus) and hover the mouse on it
# Verify that sub-menu items become visible
# Hover the mouse on the "Material" menu item, which is below
# And again move the mouse on "Rendering" 

Expected Result: Contextual sub-menus should be displayed.

Actual Result: Nothing happens. Added video in the "Attachments" section.

Reproducible with: 2023.2.0a15, 2023.2.0a17

Not Reproducible with: 2023.2.0a14, 2023.1.0b18, 2022.2.21f1, 2021.3.26f1

Confirmed OS: MacOS Monterey, Version 12.6.5; Ubuntu 22.04; Windows 10

Note: this seems to occur with menus that have been added after loading the Editor, e.g. additional Package menus. This behavior is observable with both Cinemachine and Rendering menus as these are added by packages.