SSL certificate stuck on: "Waiting on DNS propagation

Hello Netlify Support,
I connected my custom domain ktexchange.name.ng to Netlify using Netlify DNS. My domain’s nameservers have been changed to the Netlify nameservers through my registrar (HostAfrica).
The website loads, but HTTPS is not working. The SSL/TLS page sometimes says “DNS verification was successful”, but after refreshing it changes back to “Waiting on DNS propagation.”
Chrome shows NET::ERR_CERT_COMMON_NAME_INVALID and says the connection is not private.
Could you please check whether my SSL certificate provisioning is stuck and help issue the Let’s Encrypt certificate?
Thank you.