That’s a DNSviz problem (and not our bug); see: How-to sort out a problem related to the RFC 7344, Sec. 3 & Sec. 5. - #2 by peter
The IETF recently has approved a document (soon RFC) that clarifies that a digest type mismatch between CDS and DS records is fine. It says:
The parent may apply local policy in determining whether the requested update is consistent or not with the status quo
As an example of local policy, the parent may restrict the choice of hash digest types used when publishing a DS RRset (notwithstanding the requirements specified in [DS-IANA]). (The set of keys referenced in the DS RRset is not up to local policy. Only if all keys from the CDS/CDNSKEY RRsets are included, the DS RRset is considered consistent.)
In other words, the lack of digest type 4 (SHA-512) in the DS RRset is not an inconsistency in the protocol sense. I hope DNSviz will update their output once this document is an RFC.
Stay secure,
Peter