Maybe somebody mistook Sheffield for Shenfield, or used his or her GPS/smartphone app to find out where it was, and they are now embarrassed to admit this faux pas.
Historically, the North has been, along with the West Midlands, where the UK's ideas, inventions and innovation, as well as development and democracy have grown. I refer particularly to industry, science and technology.
London, is basically just "the office", and somewhere to keep an eye on the accounts, whilst the real work has been accomplished beyond the M25.
So maybe relocating the "Northern Powerhouse (Northern Office)" back to London is the right move.
We could set up a border outpost for the "North England Country" at various key crossing points, Doncaster, Crewe, Derby, and apply for membership of either the EU or Scotland. Whoever comes first?