Searching for a Greek Phrase

I don't know the answer to your question, but if you click on Analysis search you can then list by case, grouping the use of βασιλεία according whether it is in nominative or the dative. This will save you from having to look at each verse individually.

I suspect what is going on is that Logos is trying to give you every example of the phrase 'βασιλεία τῶν οὐρανῶν' irrespective of what case βασιλεία is in. It's prioritizing finding and displaying 'βασιλεία τῶν οὐρανῶν' as a whole phrase, over and above the specific case of any of the individual words. If you searched for βασιλείᾳ by itself, you'll notice it will only return results in the dative.

I to am getting the same results regardless of whatever combination of Match Case and Match all Forms is selected.