This works:
$ unbound-host -t A www.denic.de
www.denic.de has address 81.91.170.12
This does not: $ unbound-host -D -t A www.denic.de
www.denic.de has address 81.91.170.12
validation failure <www.denic.de. A IN>: signature crypto failed from 194.246.96.1 for DS denic.de. while building chain of trust
So it does seem DNSSEC-related.EDIT My explanation was wrong, this is not how keytags work. The published keytag data is consistent:
de. 3600 IN DNSKEY 256 3 8 AwEAAfRLmzuIXVf7x5A0+U7hke0dS+GEJG0EdPhnOthCCLhy0t0WqLyoXJOhnfsTJ8vQX5fd9qOJc9gyr3SWJZkXAhPm3yPSC7FWWHF70WZTKKM9CekmKdqwMwq6ZCjMSUcecCuSF4Sbt1MRszV7rFmfGVklA1l5UzNbqwD+Dr5vfcLn ;{id = 33834 (zsk), size = 1024b}
de. 3600 IN DNSKEY 257 3 8 AwEAAbWUSd/QN9Ae543xzdiacY6qbjwtZ21QfmdgxRdm4Z7bjjHWy249uqxCyjjjoS4LDoRDKmj7ElffMKvTWKE1qFKu0p8TUy4wyhX0M+m5FUjvQ3CiZMi+qY7GSHA5B+Zd73cidmnTeb3e8lso6jEsXg05/VZ2AyAqWF6FexEIFxIqiwwLk4UP0BwZ17Ur3q1qx9VSbPMyHgQ9d6nHUN1EEJsTDA2v0vKumsUyp74ZanRZ/bB/6IzpaaZyr5BLF5pSCNdbRNjVmkwYD0993vm79LueyOeibsoHRc16jhALrIJou1PFjdq7YQsYN0KtqRiJtaAfPprDBREpeamPuW/MnW0= ;{id = 26755 (ksk), size = 2048b}
de. 3600 IN DNSKEY 256 3 8 AwEAAbTe1PJi8EgIudNGb+KRTxBL2aCu5rXkZ+aIe/TC88pwRdrXYeXODp1ihZWFop5CrbWRBLrk/YUPBE8aBc6oJP+58dSkdMLYkjSkmvdvYx+zXnRLWlF2bapxvZxshATJDfGjGbCiWxKEOoyRx3UhICtHC+cUSddsEvzfacUcBb6n ;{id = 32911 (zsk), size = 1024b}
de. 3600 IN RRSIG DNSKEY 8 1 3600 20260519030655 20260505013655 26755 de. ke56T5GZt/X6zMBAF+ouyCTnAd7RY7MsnDcfa9jyyOwSouRXhvzim/V13JDTMBAnpAHxWQXoruXrAZ6A6re5N+8Pp2utVkAEKTWs0r4UOLNKoZ2+zMwNplKjNNnY5PJIbHfa5myyziLiIsi//qDIgQEACFk+pZcHXrRdqRoXPCL3UtfaXjk3+duDQdlPnYsJys5UshjVpkALSMChW7J0anzr0sG+f9ytstBneymMwFYOUC3NqbejbLPZsXGPZBQKPAoVJuV5q3znopbcqrDFfjI7bmX3QPYNvOaiT1ElBfi2piJVpDzMaMAmm2jCmvrf5VeTOBccMroh8sBtDPsaEg== ;{id = 26755}
The signature on the SOA record still does not verify: de. 86400 IN SOA f.nic.de. dns-operations.denic.de. 1778014672 7200 7200 3600000 7200
de. 86400 IN RRSIG SOA 8 1 86400 20260519205754 20260505192754 33834 de. aZoiAJ+PaHUDVSHNXfV/R26ZK3GpFB7ek2Z46VnZdmPEDaTww+a7PkiQ98W83xohUunXYSvQCMeGYfUre5UT76eBKThdxW2a6ImX9/x/oEzQ9x/69Y/NSeTckOv9m3HCLBOug01op1koiHOIAVEvonOmXEHHqo1P4sR/fNbcVg4= ;{id = 33834}