Android NavigationComponent deepLink doesn't care about actions

Question

So I have this navigation graph, and I'm implementing a deeplink to different fragments once the NEXT buton is pressed on the mainFragment.

However I encountered 2 problems:

If I call for example:

val deeplink = findNavController()
            .createDeepLink()
            .addDestination(R.id.fragmentNo5)
            .createPendingIntent()
deeplink.send()

1. The app goes from mainFragment -> fragmentNo5, and when I click back it returns to mainFragment instead of fragmentNo2.

2. Then I tested opening the fragment8 which is not even in the path by actions, and it could still open it mainFragment -> fragmentNo8

I could even add more destinations to do something as the following, which should be illegal:

mainFragment -> fragmentNo8 -> otherFragment

So I see no purpose on using deeplink this way, or is it simply a way to construct the path that I need to still know and program?

val deeplink = findNavController()
            .createDeepLink()
            .addDestination(R.id.otherFragment)
            .addDestination(R.id.fragmentNo1)
            .addDestination(R.id.fragmentNo2)
            .addDestination(R.id.fragmentNo3)
            .createPendingIntent()
 deeplink.send()