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 mxfront.stable.qloud-b.yandex.net is not the root of its zone.
Instead, try zone transfer on stable.qloud-b.yandex.net .
Instead, try zone transfer on stable.qloud-b.yandex.net .