Decentralized Identifiers (DIDs) are currently being developed by the W3C Credentials Community Group. The DID and DID Resolution specifications are constantly evolving, and so is the Universal Resolver implementation. Understand that everything about DIDs and the Universal Resolver is subject to change at any time.
DID's and DID Resolution are by definition meant to be decentralized. Under the Concentrix-passwordless domain name we are running an instance of the DID Universal Resolver, but you should not rely on this instance alone for DID resolution. From your perspective, you should treat Concentrix-passwordless as an untrusted third party that could theoretically manipulate DID Resolution results. Instead, you should run your own instance of the DID Universal Resolver or other DID Resolution tools to integrate with your applications and services.