Bottom Navigation View - Replacing Fragments is really slow

Question

I have a setup with a bottom navigation view. One of the 3 fragments I load has a tab bar with another 3 fragments. I do replace the fragments like this on bottom nav click:

    private void loadPage(int page)
    {

    if(fragmentManager == null)
        fragmentManager = getSupportFragmentManager();
    final FragmentTransaction transaction = fragmentManager.beginTransaction();
    //transaction.setCustomAnimations(R.anim.fragment_fade_in, R.anim.fragment_fade_out, R.anim.fragment_fade_in, R.anim.fragment_fade_out);
    //transaction.setCustomAnimations(R.anim.fragment_fade_in, R.anim.fragment_fade_out, R.anim.fragment_fade_in, R.anim.fragment_fade_out);

    switch (page)
    {
        //Property
        case TAB_PROPERTIES:

            Fragment fragment = fragmentManager.findFragmentByTag("property");
            if(fragment == null)
                fragment = PropertyFragment.newInstance();
            transaction.replace(R.id.rlMainContent, fragment,"property").addToBackStack("property").commit();
            break;
        //jobs
        case TAB_JOBS:
            fragment = fragmentManager.findFragmentByTag("jobs");
            if(fragment == null)
                fragment = JobsFragment.newInstance(null);
            transaction.replace(R.id.rlMainContent, fragment,"jobs").addToBackStack("jobs").commit();
            break;
        //contacts
        case TAB_CONTACTS:
            fragment = fragmentManager.findFragmentByTag("contacts");
            if(fragment == null)
                fragment = PersonalContactsFragment.newInstance(false,true,false,true);

            transaction.replace(R.id.rlMainContent, fragment,"contacts").addToBackStack("contacts").commit();

            break;
    }



}

The fragments are retrieved from the back-stack correctly, then onCreateView and onStart are called.

    @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
    View view = inflater.inflate(R.layout.activities_fragment, container, false);
    mEmptyView = view.findViewById(R.id.empty_view);
    mRecyclerView = (EmptyRecyclerView) view.findViewById(R.id.recycler_view);
    mSwipeContainer = (SwipeRefreshLayout) view.findViewById(R.id.swipeContainer_OwnerRequest);
    mProgressBar = (ProgressBar) view.findViewById(R.id.progressBar3);
    if (!mFirstStartup)
        mProgressBar.setVisibility(View.GONE);


    return view;
}


    @Override
public void onStart()
{
    super.onStart();

    if(mRecyclerView.getAdapter() == null)
    {
        mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
        mRecyclerView.setAdapter(mRecyclerAdapter);
        mRecyclerView.addItemDecoration(mHeadersDecor);
        mSwipeContainer.setOnRefreshListener(Refresh);
        mSwipeContainer.setColorSchemeResources(R.color.colorPrimary, R.color.white);


    }


}

The Fragment that is slow on loading, creates the 3 fragments above within in a pagerAdapter. Not calling setAdapter() makes it fluent, but won't render anything of course. The layout of my recyclerview is a very flat layout build with a ConstraintsLayout.

Does anyone have an idea how to handle situations like this?

I was using a pagerAdapter before and cached all 3 fragments of the bottomNavView, but I believe that is bad practice, as there is no swipe gesture, and there is no need to load and cache all the fragments.