I think I get your point and I agree with it, but I don’t think it applies to what I’m saying.
Because we cannot ignore that when a list lists other lists, those items are not members of themselves (because they are members of this list whilst they are in reference to other lists), and that when a list lists itself, that item is a member of itself (because it is a member of this list whilst it is in reference to this list itself), I think it necessary for us to have a distinction between elements in a list that are not members of themselves, and an element in a list that is a member of itself (provided that a list has elements of such a nature). No list can contain more than one element as a member of itself (the same is true of sets).
So given the above, I don’t think your post highlights a contradiction in what I said.
The list of all lists is a member of itself because it is a list. Similarly, the set of all sets is a member of itself because it is a set. If you ascribe the volume x to the set of all sets, and then say the set of all sets is the volume x, plus it contains the volume x in addition to it being the volume x, then yes, I think that is contradictory. But I am not saying that the set of all sets = volume x plus volume x when I say that it is a member of itself.