Quit the owning application and its updater, then refresh Startup Management.
Approve Touch ID or administrator authorization only when it describes the item you selected. Some modern items are controlled through System Settings → General → Login Items & Extensions or the app’s own settings.
An organization profile can prevent changes. Contact the administrator for a managed Mac.
If the item returns, its app may recreate a required helper. Disable startup in the owning app rather than repeatedly deleting its service definition.
Do not disable major macOS security controls to force the change.