ns3.systemdns.com has no TXT records.
Question and response
Question
dig ns3.systemdns.com. TXT
Answer
The response has no answer records.
Authority
systemdns.com. 300 SOA ns1.tucows.com. hostmaster.systemdns.com. 1771973851 10800 3600 2592000 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0