Chrome version 68.0.3424.0 (Official Build) canary (64-bit)
Chrome version 67.0.3396.30 (Official Build) beta (64-bit)
NVDA version 2018.1.1
JAWS version 2018.1804.26 ILM 
Windows Version 1709 (OS Build 16299.371)

Note: using a screen reader or using keyboard only yields the same results

Steps:
Launch any of above builds of Chrome. 
Move focus to omnibox
Press alt

Expected: Focus should go to access and control menu.
Actual: focus stays in omnibox.
Note: the only way to launch the menu is to move focus away from omnibox.
Reproduces in Canary and beta.