title: recyclerview inside a tablayout is only called once
body: <p>i have a recylcerview inside a tablayout, and tablayout is inside fragment (navigationview)<br>
  my problem is, recyclerview is only display/called once (initial startup of the app). after<br>
  switching to other navigationview and returning to the previous tablayout with recyclerview,<br>
  the recyclerview is not called anymore.</p>
  
  <p>here is my code :
  first tablayout</p>
  
  <pre><code>private fun setupViewPager() {
      if (Singleton.sa != null) {
          val adapter = ViewPagerAdapter(Singleton.sa!!)
          adapter.addFragment(FirstFragment(), "Recently Added")
          tab_viewpager.adapter = adapter
          tab_tabs.setupWithViewPager(tab_viewpager)
      } else {
      }
  }
  
  internal inner class ViewPagerAdapter(manager: FragmentManager):
      FragmentPagerAdapter(manager) {
  
      private val mFragmentList = ArrayList&lt;Fragment&gt;()
      private val mFragmentTitleList = ArrayList&lt;String&gt;()
  
      override fun getItem(position: Int): Fragment {
          return mFragmentList[position]
      }
  
      override fun getCount(): Int {
          return mFragmentList.size
      }
  
      override fun getPageTitle(position: Int): CharSequence {
          return mFragmentTitleList[position]
      }
  
      fun addFragment(fragment: Fragment, title: String) {
          mFragmentList.add(fragment)
          mFragmentTitleList.add(title)
      }
  }
  </code></pre>