pbx.dotroll.com has no CNAME records.
Question and response
Question
dig pbx.dotroll.com. NS
Answer
The response has no answer records.
Authority
dotroll.com. 678 SOA josh.ns.cloudflare.com. dns.cloudflare.com. 2396905323 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0