Fragment Transition leads to crash

I change fragments with an animation by swiping the screen to the right or left. Here is the parent fragment:

class StatsFragment: Fragment() {

    private lateinit var tvSortCategories: TextView
    private lateinit var tvSortMonths: TextView
    private var x: Float? = null
    private val fragmentStatsCat = StatsCategoryFragment()
    private val fragmentStatsMon = StatsMonthFragment()


    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        val view: View = inflater.inflate(R.layout.fragment_stats, container, false)
        tvSortCategories = view.findViewById(R.id.tvStatsCategories)
        tvSortMonths = view.findViewById(R.id.tvStatsMonths)
        tvSortCategories.isSelected = true
        tvSortCategories.setOnClickListener {
            inflateCategory()
        }
        tvSortMonths.setOnClickListener {
            inflateMonth()
        }
        childFragmentManager.beginTransaction()
        .replace(R.id.stats_container, fragmentStatsCat)
        .commit()

        view.setOnTouchListener {_, event ->

            when(event.action) {
                MotionEvent.ACTION_DOWN -> {
                    x = event.x
                }
                MotionEvent.ACTION_MOVE -> {
                    if(x != null) {
                        val dx = event.x - x!!
                        if(dx > 200f) {
                            inflateCategory()
                            x = event.x
                        }
                        if (dx < -200f) {
                            inflateMonth()
                            x = event.x
                        }
                    }
                }
            }

            true
        }

        return view
    }

    private fun inflateCategory() {
        tvSortCategories.isSelected = true
        tvSortMonths.isSelected = false

        childFragmentManager.beginTransaction()
        .setCustomAnimations(R.anim.slide_in_left, R.anim.slide_out_right)
        .replace(R.id.stats_container, fragmentStatsCat)
        .commit()
    }

    private fun inflateMonth() {
        tvSortCategories.isSelected = false
        tvSortMonths.isSelected = true

        childFragmentManager.beginTransaction()
        .setCustomAnimations(R.anim.slide_in_right, R.anim.slide_out_left)
        .replace(R.id.stats_container, fragmentStatsMon)
        .commit()
    }
}

This works fine, but with one exception. When I perform a fragmentTransaction, while the old fragmentTransaction has not finished, it crashes with a ´java.lang.IllegalStateException´: ´Restarter must be created only during owner's initialization stage´

Is there a way I can check if the old transaction has finished before performing a new one?

EDIT: To further explain what exactly I want to do:

I want to change between those two Child Fragments by either swiping over the creen to the other fragment or by touching on ´Sort by Categories/Months´.