Android - AutoCompleteTextView only works when the opposite

I have AutoCompleteTextViewone that dynamically updates the list of offers by user type. My problem is that as you enter the list, the list is updated, but the drop-down list does not appear! But when I delete the character (backspace), a popup menu appears!

I even tried to explicitly call autoText.showDropDown();after changing the text, but it does not work.

Here is mine TextChangedListener:

private TextWatcher textChecker = new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {

    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
        if(autoText.length()>9){
            new GeoTask().execute();
        }
    }

    @Override
    public void afterTextChanged(Editable editable) {
        if(autoText.length()>9){
            autoText.showDropDown();
            Log.i("UPDATE","showDropDown");
        }
    }
};

I even tried resetting the adapter above autoText.showDropDown();, but still nothing:

autoText.setAdapter(null);
autoText.setAdapter(adapter);

Is there any way to make it work?

EDIT . Here is the complete action code. Maybe someone can find what I'm doing wrong ...

public class TestDoctor extends Activity {

    TextView latText;
    TextView lngText;
    AutoCompleteTextView autoText;
    ArrayAdapter<String> adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.test_doctor);

        latText = (TextView) findViewById(R.id.latTextView);
        lngText = (TextView) findViewById(R.id.longTextView);
        autoText = (AutoCompleteTextView) findViewById(R.id.autoCompleteTextView);


        Button button = (Button) findViewById(R.id.buttonDoctor);
        button.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                new GeoTask().execute();
            }
        });
        autoText.setThreshold(10);
        autoText.setHint("Οδός Αριθμός, Περιοχή");
        adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line);
        autoText.setAdapter(adapter);
        adapter.setNotifyOnChange(true);
        autoText.addTextChangedListener(textChecker);
    }

    private TextWatcher textChecker = new TextWatcher() {

        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3){}

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
            if(autoText.length()>9){
                new GeoTask().execute();
            }
        }

        @Override
        public void afterTextChanged(Editable editable) {}
    };

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    private List<SimpleAddress> getAddressesFromText(String address) {
        address = address.replace(' ', '+');
        HttpHelper httpHelper = new HttpHelper();
        InputStream inputStream = httpHelper.makeHttpGetRequest("http://maps.google.com/maps/api/geocode/json?address=" + address + "&sensor=false");
        String response = httpHelper.inputStreamToString(inputStream);

        List<SimpleAddress> simpleAddresses = new ArrayList<SimpleAddress>();
        try {
            JSONObject jsonObject = new JSONObject(response);


            int size = ((JSONArray) jsonObject.get("results")).length();

            for (int i = 0; i<size; i++){
                String formatted_address = ((JSONArray) jsonObject.get("results")).getJSONObject(i)
                        .getString("formatted_address");

                Double lng = ((JSONArray) jsonObject.get("results")).getJSONObject(i)
                        .getJSONObject("geometry").getJSONObject("location")
                        .getDouble("lng");

                Double lat = ((JSONArray) jsonObject.get("results")).getJSONObject(i)
                        .getJSONObject("geometry").getJSONObject("location")
                        .getDouble("lat");
                simpleAddresses.add(i,new SimpleAddress(formatted_address,lat,lng));
            }
            return simpleAddresses;
        } catch (JSONException e) {
            return null;
        }
    }

    public class GeoTask extends AsyncTask<Void, Void, Void> {
        List<SimpleAddress> simpleAddresses = new ArrayList<SimpleAddress>();

        @Override
        protected Void doInBackground(Void... voids) {
            Log.i("UPDATE","1");
            try {
                simpleAddresses = getAddressesFromText(autoText.getText().toString());
            } catch (NullPointerException e) {
            }
            Log.i("UPDATE","2");
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            Log.i("UPDATE", "3");

            int size = simpleAddresses.size();

            if(size > 0){
                adapter.clear();
                Log.i("ADAPTER_SIZE",""+size);
                for (int i = 0; i< size; i++){
                    adapter.add(simpleAddresses.get(i).getFormatted_address());
                    Log.i("ADDED",simpleAddresses.get(i).getFormatted_address());
                }
                Log.i("UPDATE","4");
                autoText.setAdapter(null);
                autoText.setAdapter(adapter);
                autoText.showDropDown();
                Log.i("UPDATE","showDropDown");
            }
            super.onPostExecute(aVoid);
        }
    }
}

2 , . , backspace...

@Override
public void afterTextChanged(Editable editable) {
    runOnUiThread(updateAdapter);
}

...

private Runnable updateAdapter = new Runnable() {

    public void run(){
        Log.i("ADAPTER_UPDATE","start");
        adapter.notifyDataSetChanged();
        autoText.showDropDown();
        Log.i("ADAPTER_UPDATE","end");
    }
};

, . , . , logcat . . , , ?!!