Apps · Safety badges and blocked apps
Why does an app that starts at login get an Override badge?
Short answer: It registers an automatic start that points at its exact location. After a move, auto-start can fail if the external drive isn't connected yet at login.
The app has something registered with macOS to start automatically that points at the app's exact location. After a move it may still work, but at early start-up your external drive might not be connected yet — so the app's automatic start can fail.
If you always have the drive connected when you log in, it's often fine. Otherwise keep apps that must start at login on your built-in drive.