ns.2gis.RU has no CNAME records.
Question and response
Question
dig ns.2gis.RU. NS
Answer
The response has no answer records.
Authority
2gis.RU. 1176 SOA ns.2gis.RU. hostmaster.2gis.RU. 2026030251 1200 300 2592000 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0