Chrome 65.0.3300.0 Canary
NVDA 2017.4

Steps to repro:
# With NVDA running, visit google.com
# Tab to the search button
# Press NVDA+shift+m to move the mouse to the search button
# Press alt+f
# Notice that the Chrome menu opens, but no sub menus
# Press up arrow to 'Help'
# Press NVDA+shift+m to move the mouse to the help menu
# Notice that the submenu doesn't open
# Press escape to close the menu
# Press alt+f
# Notice that the help submenu immediately opens

Expected: Submenu should never open via alt+f

Actual: Submenu opens of mouse pointer lands on the submenu on menu open