I am unsure how to add some DNS records to cpanel for a site.
20 years ago I’ve seen DNS configurators that require e.g.
www.domain.com. as the full record descriptor, but I haven’t seen that in over a decade. I’m not sure what you’re using to configure your DNS, but check those docs to find out. If it requires the domain name as part of the descriptor, it likely would for TXT records as well.