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 53B55840-E7E7-11EC-BB6B-1CD00E312B2E._domainkey.cbs.mpg.de is not the root of its zone.
Instead, try zone transfer on cbs.mpg.de .
Instead, try zone transfer on cbs.mpg.de .