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 client-0.ipv6.sin02.ds.network is not the root of its zone.
Instead, try zone transfer on ipv6.sin02.ds.network .
Instead, try zone transfer on ipv6.sin02.ds.network .