WorldCat Identities is apparently been discontinued since March 26th
https://www.oclc.org/developer/api/oclc-apis/worldcat-identities.en.html
Old links now redirect to WorldCat Entities which have their own URI

https://www.worldcat.org/identities/ is 404 but from Google cache:

The OCLC Research WorldCat Identities project is ending. The work provided valuable insight into how to mine bibliographic data for insight into the People and Organizations that create and serve as subjects library materials. The findings demonstrated the power of data mining over the world’s largest set of bibliographic metadata and highlighted the value of collaborative collective cataloging. The WorldCat Identities data has positively impacted OCLC’s work to build the WorldCat Entities application and the 150 million Person and Work descriptions accessible through it. This work will continue to build our entity ecosystem to support the future knowledge work of librarians.

The WorldCat Identities web application will be retired and shut down in the coming months and the data is no longer being updated. The most recent version of the data is from July of 2022. As OCLC continues to build out the WorldCat Entities ecosystem, please use it as a source for persistent Person identifiers. https://id.oclc.org/worldcat/entity

Sting https://musicbrainz.org/artist/7944ed53-2a58-4035-9b93-140a71e41c34
used to be https://www.worldcat.org/identities/lccn-n84157839 and is now https://id.oclc.org/worldcat/entity/E39PBJtCD4cBkp4m9Gfb88jKVC

The new URI needs to be whitelisted, URL cleanup updated (to remove potential ".html" at the end of the URL) and existing WorldCat links updated (if possible)