Changes since SOA version
IXFR is a zone transfer request that returns changes since a specific SOA version. Enter the SOA version to request changes since then.
Not an apex domain
The domain ward-15-b2-v4wan-167229-cust922.vm18.cable.virginm.net is not the root of its zone.
Instead, try zone transfer on vm18.cable.virginm.net .
Instead, try zone transfer on vm18.cable.virginm.net .