Dropdown not showing in Kotlin Android

Question

I am using array and HashMap to sort Firebase child with children count and setting that into a dropDown array in Lotlin list. The problem is the dropdown items are not displayed. I need to sort Firebase child Like political with its child count and I try to adding that into ArrayAdapter of dropdown like this:

adapbl = ArrayAdapter<String>(this,R.layout.dropdownbl,keyarray)

autocomplete.setAdapter(adapbl)

Firebase database image:

Dropdown not displayed image:

Activity code:

class TrendingPosts : AppCompatActivity() {
    private lateinit var bottomnav : BottomNavigationView
    private var pTime : Long = 0
        private lateinit var itembl: Array<String>
        private lateinit var adapbl : ArrayAdapter<String>
        private lateinit var autocomplete : AutoCompleteTextView
        private lateinit var content: ArrayList<String>
        private lateinit var keyarray: Array<String>
        override fun onCreate(savedInstanceState: Bundle?) {
            super.onCreate(savedInstanceState)
            setContentView(R.layout.activity_trending_posts)
             content = ArrayList<String>()
             
             content.add("POLITICAL")
            content.add("ENTERTAINMENT")
            content.add("SOCIAL")
            content.add("ENVIRONMENT")
            var  hm = HashMap<String,String>()

            for(item : String in content ){
                val database: FirebaseDatabase = FirebaseDatabase.getInstance()
                val myRef: DatabaseReference = database.getReference("ContentType").child(item)

                myRef.addValueEventListener(object : ValueEventListener{
                    @SuppressLint("SetTextI18n")
                    override fun onDataChange(snapshot: DataSnapshot) {
                        val text:String = snapshot.childrenCount.toString()
                            hm.put(item,text)
                    }

                    override fun onCancelled(error: DatabaseError) {

                    }
                })
            }
            var sortedmap = hm.toList().sortedBy{
                (k,v)-> v }.toMap()
            keyarray = sortedmap.keys.toTypedArray()

            autocomplete = findViewById(R.id.BL_Lang_On)

            
            adapbl = ArrayAdapter<String>(this,R.layout.dropdownbl,keyarray)
            autocomplete.setAdapter(adapbl)
            autocomplete.setOnItemClickListener{ parent,view,position,id ->
                val languages : String = parent.getItemAtPosition(position).toString()
                createSnackbar(
                    "SELECTED: "+languages
                )

            }

            bottomnav = findViewById(R.id.bottomnavigation)
            bottomnav.selectedItemId = R.id.ctrend
            bottomnav.setOnNavigationItemSelectedListener { item ->
                when(item.itemId){
                    R.id.home ->{
                        startActivity(Intent(this, MainActivity::class.java))
                        overridePendingTransition(0,0)
                        
                        true
                    }

                    R.id.cv ->{
                        startActivity(Intent(this, activity_for_playing_soma_videos::class.java))
                        overridePendingTransition(0,0)
                        
                        true
                    }

                    R.id.ch ->{
                        startActivity(Intent(this, ForSomasunthaVideoActivity_CH::class.java))
                        overridePendingTransition(0,0)
                        
                         true
                    }

                    R.id.ctrend ->{
                        overridePendingTransition(0,0)
                         true
                    }

                    R.id.csearch->{
                       // return true
                        
                        startActivity(Intent(this, Search::class.java))
                        overridePendingTransition(0,0)
                        true
                    }
                 
                }
                 false
            }
        }

        private fun createSnackbar(message: String){
            val mainsh: View = findViewById(R.id.trendcons)
            Snackbar.make(mainsh, message, Snackbar.LENGTH_SHORT).show()
        }
    }

I got fixed this by adding runOnUiThread {}.