It looks like docker-registry made a breaking change on Oct 19th, 2023:

distribution/distribution#4096

As a result the kid field of the JWT token is no longer valid - the code to process the the values produced by docker-libtrust has been removed from docker-registry completely. It is not clear if the kid format just needs to be updated or if there are additional fields needed.

It looks like the last docker-registry commit that will work with the current docker-auth is 1d410148efe6d1b7fd56457507a9dd465b105ec4