Activity instance does not refill again after onDestroy

Question

I have an interface:

interface PermissionLauncher<in T> {
    fun bindLauncher(launcher: T)
    fun updatePermissionsStatus()
}

And I implemented it for activities:

class BindLauncherException : IllegalAccessException(
    "You must call bindLauncher method in your onCreate() function",
)

class ActivityPermissionLauncher :
    PermissionLauncher<FragmentActivity>, LifecycleEventObserver {

    private var _activity: FragmentActivity? = null
    private val activity get() = _activity ?: throw BindLauncherException()

    override fun onStateChanged(source: LifecycleOwner, event: Lifecycle.Event) {
        when (event) {
            Lifecycle.Event.ON_DESTROY -> {
                activity.lifecycle.removeObserver(this)
                _activity = null
            }
            else -> {
                // No need to handle
            }
        }
    }

    override fun updatePermissionsStatus() {
        // update permission status with the activity instance
    }

    override fun bindLauncher(launcher: FragmentActivity) {
        _activity = launcher
        activity.lifecycle.addObserver(this)
    }

}

Now in my activities I use it like this:

class PrivacyAndTermActivity : FragmentActivity(),
    PermissionLauncher<FragmentActivity> by ActivityPermissionLauncher() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        bindLauncher(this)
        myButton.setOnClickListener {
            updatePermissionsStatus()
        }
    }
}

Now everything works fine in my test devices. but in crashlytics it seems that some devices are crashing with BindLauncherException.

I put that exception to inform the developer not to forget calling bindLauncher in onCreate function of delegated activity. But I don't know why even that I'm calling it in my onCreate some users still getting the error. Because I clear my activity instance only in onDestroy and it should be refill in onCreate again.