Combo Box String widget doesn't change color via function

Attempting to change the Foreground color of a Combo Box String in the Graph tab of the owning widget Blueprint has no effect.

Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL - 4753647), 4.22.3 (CL - 7053642), 4.23 (CL - 8386587), 4.24 (CL - 9023396)

1. In a blank C++ project, create a Blueprint Function Library
2. In that library, add in the following code:
   Header:

   UFUNCTION(BlueprintCallable, Category = "CustomFunctions") static void SetComboboxTextColor(UComboBoxString* ComboboxIn, FSlateColor NewColor);

   Source:

   void <BlueprintFunctionLibraryName>::SetComboboxTextColor(UComboBoxString* ComboboxIn, FSlateColor NewColor) {ComboboxIn->ForegroundColor = NewColor;}

1. Create a Widget Blueprint with a Combo Box String in its canvas in the Designer tab
2. In the Graph tab, call the above function on the Combo Box String
3. Have the Level Blueprint construct the above widget to the screen on BeginPlay
4. PIE

Expected: The color of the Combo Box String widget would change

Result: The Combo Box String does not respect the function call