>>108761869
The cause appears to be a failed DNSSEC ZSK rollover at DENIC. DENIC signed zone data with the ZSK key tag 33834, but did not publish this key in the DNSKEY record. Every DNSSEC-validating resolver considers the signature invalid and responds with SERVFAIL and the following error:
EDE: 6 (DNSSEC Bogus): RRSIG with malformed signature found for de/soa (keytag=33834)