An ID mismatch occurs when the ID on your DNS query differs from the ID on your DNS response. Queries & Responses should share the same ID - either this has been done intentionally or it's a sign that something is buggy with the resolver.
This sounds like a serious, security vulnerability. We'll investigate it in 3-5 years
More saliently, the overwhelming majority of the Linux kernel's direct and extended userbase has contributed nothing at all directly to the Linux kernel, as just one example.
Due to several lawsuits and criminal investigations, DN$ needs to shutdown. Source code to setup your own DN$ resolver is here.