Title and map search discrepancy

We are selling our property title number GM618943. Our buyers solicitor has produced a map search document that shows our ownership to also own part of our neighbours property. This is different to our title and didn't come up when we purchased our property. We surely don't suddenly own part of our neighbours property! Our solicitor says she has raised this with land registry and has had no reply. We are simply seeking clarification of the title and I can't understand how this map search is so different to the title we got when we purchased the property. The buyers solicitor has said she can't accept general boundary rules so we feel rather stuck. Any help we would be really grateful for. Thank you. 

Map search doc

Title doc

Eleanor - MapSearch is not definitive re the registered extent/general boundaries and you are already aware of that. The title plan is the definitive detail any seller/buyer should go by.
MapSearch is a tool to enable users to identify registered titles and then obtain and consider the actual registered information, namely the register and title plan.
So they are using it correctly but then going too far by querying/relying on the detail re the actual sale/purchase/conveyancing.
Having said that things should match up so I'd suggest using our Contact form to flag the issue so the support team can amend the details as appropriate. We can't do it via this forum