When the Category specifier of a UPROPERTY has more than one word, using the UCLASS specifier HideCategories requires the category name to be written all as one word even if the UPROPERTY is separated by spaces.
Both (Category = "New Random Category") and (Category = "NewRandomCategory") would require UCLASS(HideCategories = ("NewRandomCategory"))
This could be confusing since the syntax of the categories does not match.
Choice variable is visible in the editor even though the Category and HideCategories names match.
Properties are hidden when HideCategories string matches Category name string
Head over to the existing Questions & Answers thread and let us know what's up.