SSL 4 Subdomain Error: DNS_PROBE_FINISHED_NXDOMAIN

Hi,

I got ssl cert active on my root domain for: https://architectden.com/

but its been 48hrs and still no change in my subdomains

https://top-3-virtual-design-and-construction-vdc-workflows.architectden.com
https://how-to-implement-vr-architecture-technology.architectden.com

here is the error message:
This site can’t be reached how-to-implement-vr-architecture-technology.architectden.com’s server IP address could not be found.
DNS_PROBE_FINISHED_NXDOMAIN

please help
thanks!

https://community.cloudflare.com/search?q=DNS_PROBE_FINISHED_NXDOMAIN