Maps have gone weird on Amundson on 2011 Octavia

In the last few weeks, the maps on our Sat Nav are not displaying correctly, it shows areas near by, but not exactly where we are.  For example we can drive down our main road but it shows us driving across the local river, over fields and on streets nearby - we reckon it is calculating the distance to destination reasonably correctly, but it is otherwise useless.

Is this something that an update to the maps would fix or is it something wrong with the systems ability to identify where we are?

Anyone any ideas if it is fixable?  We also have Maxidot if that makes any difference.

I found the software portal and put in our VIN number but is says no updates available.

Thanks