When you double-click on a menu button in the Customize menu (Automations, Sections, etc), it oddly navigates through two lists. You need to click on the back button twice to get to the Customize menu.
It depends if the area where you click has no other clickable item in the next list. I can’t replicate it for Fields for example.
This usually happens when you double-click on Forms, Emails, Task types, Bundles etc where there is nothing to click on in the next menu.
Minor bug but thought it might get added to the backlog 
