possible duplicates Android : autocompletetextview, suggestion list displays above the textview?
I am fully trying to display suggestion list overlapping on keyboar
I've had this problem before. For me, there was more screen space above the AutocompleteTextView than below (testing on a "normal" device), so the list opened upwards. I adjusted my layout slightly so that there was more space below the AutocompleteTextView and it started opening downwards. That's what fixed it for me.