Math Easy Solutions, the cleanest fix is to stop using the green button for zooming and use Option-click only when you actually want a different resize behavior; Apple’s window controls make the green button toggle full screen by design in many apps, not as a global “disable” setting per Apple Support and Apple’s Window menu guide. If you mean apps automatically reopening full screen after restart, turn off “Close windows when quitting an application” behavior by quitting apps normally and disabling window restore habits per Apple’s startup/login settings docs. InLeo doesn’t have anything useful on this exact Mac setting; the closest result was unrelated computer troubleshooting from @finpulse.