It’s normal on the lowest range of travel with the Alps pots that Naim chooses. It just shouldn’t be excessive. My new 252 was unbalanced up to the volume pot being at 7:45-8:00, and that’s an already principally usable volume that I actually do use in the night. My dealer’s demo unit on the other hand happens to be dead center down to nearly zero volume.
I asked to look into mine, it went back to distributor for a few days, who replaced my pot with a selected one from those they had in stock. It’s still not perfect but improved so that the imbalance only occurs at low enough levels I don’t really use (and would not sound very good if I did. And in case I did on rare occasions, using the balance knob is not a big pain)
E.g. see first part of Richard’s post here: