This happens even with SIP disabled. As soon as dtrace is terminated, the application continues execution. This happens with all apps. Nothing obvious in Console. How can I fix this?

I'm trying to understand the mechanism by which the Quit Application menu item gets disabled while a modal dialog/alert is up. Who is responsible for disabling the menu item? We have a case where in some cases, the Quit Application menu item is not getting disabled even when a modal dialog is up. So I'm trying to figure out where things may be going wrong.