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 _97cf42cdf71a5f50225e7de71bbb4e23.xlfgrmvvlj.acm-validations.aws is not the root of its zone.
Instead, try zone transfer on xlfgrmvvlj.acm-validations.aws .
Instead, try zone transfer on xlfgrmvvlj.acm-validations.aws .