It's impossible to say something without a code.
For example, I see StopService (Starter). In B4A 8.3 Destroy event happens, but service continue to work. Probably, you app doesn't expect this.
Or ExitApplication. It not always kills the application. B4A uses System.exit (0), which restarts the app with one fewer activity on the stack.
So, if you called activity Two from activity Main, and System.exit (0) is called in activity Two, then the application will be killed and started immediately with only one activity (Main). See attached sample