Handle non positional input only when opened

osu.Game/Graphics/UserInterface/OsuDropdown.cs

@@ -51,6 +51,8 @@ private void updateAccentColour()
         #region OsuDropdownMenu
         protected class OsuDropdownMenu : DropdownMenu, IHasAccentColour
         {
+            public override bool HandleNonPositionalInput => this.State == MenuState.Open;
+
             // todo: this uses the same styling as OsuMenu. hopefully we can just use OsuMenu in the future with some refactoring
             public OsuDropdownMenu()
             {