Why one entity is a List Object?
There are many such cases.
They are in one level/one region/province.
    
    CityData[{"Anqing", "Anhui", "China"}]
    (* Entity["City", {"Anqing", "Anhui", "China"}] *)

    CityData[{"Bangbu", "Anhui", "China"}]
    (* {Entity["City", {"Bengbu", "Anhui", "China"}]} *)

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/wH4S4m.png