error when expanding maps

Put the summary of the bug you're having here

What I expected to happen was...:
Describe what you thought should happen here
when taking an existing map and adding paper I expect the new map to keep centred on the original start point for the map

What actually happened was...: On expanding the map the origin is pinned near the top left hand corner
Describe what happened here

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here Placve map on crafting table
2. ...place paper all round the map
3. ...lift new map off and activate/view