apparently, Picker doesn't really care about the sort flag (confirmed with Sebastien Grenier)

Author: K-Tone

Packages/com.unity.inputsystem/InputSystem/Editor/PropertyDrawers/InputActionReferenceSearchProviders.cs

@@ -12,7 +12,7 @@ internal static class SearchConstants
         // SearchFlags: these flags are used to customize how search is performed and how search
         // results are displayed in the advanced object picker.
         // Note: SearchFlags.Packages is not currently used and hides all results from packages.
-        internal static readonly SearchFlags PickerSearchFlags = SearchFlags.Sorted | SearchFlags.OpenPicker;
+        internal static readonly SearchFlags PickerSearchFlags = SearchFlags.OpenPicker;
 
         // Search.SearchViewFlags : these flags are used to customize the appearance of the PickerWindow.
         internal static readonly Search.SearchViewFlags PickerViewFlags = SearchViewFlags.DisableBuilderModeToggle