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 _441ac89ce40cf8f09fb5731ff67f89ba.mhbtsbpdnt.acm-validations.aws is not the root of its zone.
Instead, try zone transfer on mhbtsbpdnt.acm-validations.aws .
Instead, try zone transfer on mhbtsbpdnt.acm-validations.aws .