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 _14e309e571de42c753ca414e2e5c06b5.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 .