For the purposes of clarification we are linking to the following extract from The Boundary Commission for England review of Parliamentary Constituencies, which we hope might help.
“The Borough of Milton Keynes is currently divided into two constituencies, both of which have electorates above the 5% limit. Additionally, the local government ward boundaries in the borough have also been modified. In order to reduce the electorates of the two Milton Keynes constituencies it is necessary to cross the boundary between the Borough of Milton Keynes and Buckinghamshire. We therefore propose to include the Wolverton and Stony Stratford wards of the Borough of Milton Keynes in our proposed Buckingham constituency.”
Here is the boundary information https://www.bce2018.org.uk/
Here are two map extracts which visually indicate the change to our boundaries (taken from a zoomed in view at http://constituencyboundaries.uk/2016/south-east )


and here is where people can comment https://www.bce2018.org.uk/
As we have already stated, we are delving into this issue more deeply, and will post any more information we can find right here as soon as we have any. If you are reading this and have any further insight, please contact us so we can share the information with everybody.
Thanks to David for his help in finding the appropriate links and extracts listed above.
UPDATE: From The FAQs at BCE consultation Portal (follow the link for more Frequently asked questions and answers)