The reason the “Live SSL Status” says that your subdomain doesn’t have a valid SSL certificate is because it doesn’t have a valid SSL certificate.
And the reason the certificate you installed on our hosting is not taking effect on that subdomain is because we are not hosting that subdomain.
Your subdomain is pointing to Netlify. That means that for SSL to work on your subdomain, you must have SSL setup at Netlify.
Setting up SSL on our end is a waste of time, because it has no effect on a website that’s not hosted with us. For the same reason, there is also no need to add it to your hosting account as a Subdomain, you only need that if you actually want to host the subdomain with us.
I recommend you remove the subdomain from our panel if you don’t intend to host it with us. I cannot guarantee that we’ll never “fix” the DNS records on our end to point your subdomain to our servers, removing the connection to Netlify.
Custom TXT records are not supported in our nameservers. Instead, you can use other nameservers instead, either from your domain name provider, or from a specialized provider like Cloudflare. You can point your domain or any subdomain you want to host with us to the website IP on our hosting: