ipv6.http2.web.yas-online.net has no CNAME records.
Question and response
Question
dig ipv6.http2.web.yas-online.net. NS
Answer
The response has no answer records.
Authority
web.yas-online.net. 494 SOA ch.ch-inter.net. admin.neic0.de. 2019112103 10800 3600 604800 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0