May I firstly ask is
yourdomain.com added to your Cloudfalre account and has got Cloudflare nameservers?
What is the domain name we are talking here about?
Furthermore, that other page is on some sub-domain like
sub.yourdomain.com or how?
May I suggest following the instructions from below:
May I also ask what SSL option have you got selected under the SSL/TLS tab of Cloudflare dashboard at your Cloudflare account for your domain name? (Flexible, Full, Full Strict …)