EDIT

The "New Taxon" dialog (when opened from search taxon selection dialog, e.g. when selecting a new taxon for a misapplied name or selecting a taxon for a concept relationship) does by default use "NonViral" as nomenclatural code.
Better it should take the nom code given by the context. E.g. in a taxon relationship it should take the nom code of the related taxon. Same for a misapplied name. Or simply refer to the nom code defined in the CdmPreference (if given). The later I haven't checked if it is already the case.