spf.masterbase.com has no CNAME records.
Question and response
Question
dig spf.masterbase.com. NS
Answer
The response has no answer records.
Authority
masterbase.com. 1493 SOA lovisa.ns.cloudflare.com. dns.cloudflare.com. 2397047605 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0